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    <link:label id="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_b07e2516-ff19-4c59-9dfc-850b388335da_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Changes in operating assets and liabilities:</link:label>
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    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_33c091d5-212f-40e4-a3fa-2d9a5de7ecef_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2028</link:label>
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    <link:label id="lab_us-gaap_AccountsReceivableNetAbstract_871b817b-8519-4e05-9a9a-359bc1652d6e_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsReceivableNetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts Receivable, after Allowance for Credit Loss [Abstract]</link:label>
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    <link:label id="lab_iclr_DeferredTaxAssetContractWithCustomerLiability_documentation_en-US" xlink:label="lab_iclr_DeferredTaxAssetContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Deferred Tax Asset, Contract With Customer, Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_DeferredTaxAssetContractWithCustomerLiability" xlink:href="iclr-20231231.xsd#iclr_DeferredTaxAssetContractWithCustomerLiability"/>
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    <link:label id="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock_b5ce54cd-d5ec-491e-a742-7a179928bb5e_terseLabel_en-US" xlink:label="lab_us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share Capital</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsByGeographicalAreasTableTextBlock_3444abbf-26e2-46c4-992b-55dc9b3c7d83_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsByGeographicalAreasTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Distribution of Net Revenue by Geographical Area</link:label>
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    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherNonCurrentLiabilities_7b1a3fc0-b9e5-4b07-934f-d01076b7ce49_terseLabel_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherNonCurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other non-current liabilities</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_a3676479-be43-4bcf-966a-1ab52625b900_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Dividend yield (in percent)</link:label>
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    <link:label id="lab_srt_MajorCustomersAxis_031cf6d9-53b2-4ac5-abb5-af5e4173fdd5_terseLabel_en-US" xlink:label="lab_srt_MajorCustomersAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Customer [Axis]</link:label>
    <link:label id="lab_srt_MajorCustomersAxis_label_en-US" xlink:label="lab_srt_MajorCustomersAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Customer [Axis]</link:label>
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    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_6edcad7c-e105-44b1-b620-64655f8993fc_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2026</link:label>
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    <link:label id="lab_iclr_OtherUndenominatedCapitalMember_8bf98297-dbcd-4350-9de7-be6303b93125_terseLabel_en-US" xlink:label="lab_iclr_OtherUndenominatedCapitalMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Undenominated Capital</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentLineItems_39e432c7-c114-4a13-b58a-ff8376c3f62f_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Property, Plant and Equipment [Line Items]</link:label>
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    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_1e893ac9-b517-48e7-b7b2-64c2f1d7bd97_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2025</link:label>
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    <link:label id="lab_us-gaap_InvestmentIncomeInterest_1a29de8f-6605-4f4a-a8de-58d0ae6db12f_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentIncomeInterest" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest income</link:label>
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    <link:label id="lab_us-gaap_BusinessCombinationConsiderationTransferred1_62e08196-e11b-40ed-b8e3-a2564e90ced1_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationConsiderationTransferred1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business combination, consideration transferred</link:label>
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    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_ff23c3a0-ad5a-4d59-9882-02cc172f2956_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Unearned revenue (Note 4)</link:label>
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    <link:label id="lab_us-gaap_ContractWithCustomerLiabilityCurrent_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Contract with Customer, Liability, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:to="lab_us-gaap_ContractWithCustomerLiabilityCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_99902837-4c3c-4766-aa34-8059222762cb_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Summary of Weighted Average Fair Values and Assumptions Used</link:label>
    <link:label id="lab_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]</link:label>
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    <link:label id="lab_dei_SecurityExchangeName_e0aacdc8-c0dd-4bc3-8ae7-3e99a71db3a7_terseLabel_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Security Exchange Name</link:label>
    <link:label id="lab_dei_SecurityExchangeName_label_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Security Exchange Name</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_f565c749-da44-4aa8-b7ad-451dda596609_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-Based Compensation</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-Based Payment Arrangement [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy"/>
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    <link:label id="lab_us-gaap_SellingGeneralAndAdministrativeExpense_c1a0a086-e8b0-4c29-9d52-31610890ab21_terseLabel_en-US" xlink:label="lab_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Selling, general and administrative</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:to="lab_us-gaap_SellingGeneralAndAdministrativeExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_4be7d75a-cb38-48c5-98fa-aaa660d4e07c_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated other comprehensive loss (Note 25)</link:label>
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    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherCurrentAssets_8aa2646f-16f8-4a15-9dba-7b40a7c43b2b_terseLabel_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherCurrentAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other current assets</link:label>
    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherCurrentAssets_label_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherCurrentAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Current Assets</link:label>
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    <link:label id="lab_us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureNoncurrentTextBlock_ed31d51c-e923-420d-b4d0-ae4ef7b933e1_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureNoncurrentTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Non-current other liabilities</link:label>
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    <link:label id="lab_us-gaap_EmployeeStockOptionMember_9c654002-a254-473f-bfff-8f833d17c51d_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeStockOptionMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Employee Stock Option</link:label>
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    <link:label id="lab_us-gaap_InvestmentPolicyTextBlock_91715dfd-914f-4a86-b4d1-34b4449e960c_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Investment in Debt, Equity and Other</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_0c05cc56-7d4e-4188-8581-7938d1ef322c_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Restructuring Charges</link:label>
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    <link:label id="lab_dei_DocumentType_c7a6b5df-aa15-44a0-acbf-b9a1f2284350_terseLabel_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Type</link:label>
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    <link:label id="lab_us-gaap_OtherComprehensiveIncomeLocationDomain_5cbf831f-77b9-42a1-8f4a-d80c88538664_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLocationDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Comprehensive Income Location [Domain]</link:label>
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    <link:label id="lab_us-gaap_GeographicConcentrationRiskMember_b6f05894-6920-4244-8d45-2983f4ed5b59_terseLabel_en-US" xlink:label="lab_us-gaap_GeographicConcentrationRiskMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Geographic Concentration Risk</link:label>
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    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccountsPayable_c7339e20-2455-4f10-891b-2bde9c9b836c_terseLabel_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentAccountsPayable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts payable</link:label>
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    <link:label id="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_4d132837-e5bd-4c5b-9820-f3bb1291d7ff_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Additional operating loss carryforward</link:label>
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    <link:label id="lab_us-gaap_DerivativeLiabilitiesCurrent_80469cbd-e664-43cf-a052-05c677c33c91_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative liability, current</link:label>
    <link:label id="lab_us-gaap_DerivativeLiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_DerivativeLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Liability, Current</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeLiabilitiesCurrent" xlink:to="lab_us-gaap_DerivativeLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_Range4Member_cde1538c-2870-4bd5-ba2f-c53f72bdf71a_terseLabel_en-US" xlink:label="lab_iclr_Range4Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Range 4</link:label>
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    <link:label id="lab_iclr_DefinedBenefitPlanBenefitObligationBenefitsPaidAndIncreaseDecreaseForBalanceTransfers_ac6006a8-385e-4f1b-9a85-7ac26fb0cd9c_verboseLabel_en-US" xlink:label="lab_iclr_DefinedBenefitPlanBenefitObligationBenefitsPaidAndIncreaseDecreaseForBalanceTransfers" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Benefits paid and transferred balances</link:label>
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    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCurrentPortionOfOperatingLeaseLiabilities_900e2d95-4054-4f5b-8c52-ade320f787fd_terseLabel_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCurrentPortionOfOperatingLeaseLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Current portion of operating lease liabilities</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:to="lab_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherNoncashIncomeExpense_c78f9565-5e58-49e7-bd83-7e6748430ba4_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other non-cash items</link:label>
    <link:label id="lab_us-gaap_OtherNoncashIncomeExpense_label_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Noncash Income (Expense)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherNoncashIncomeExpense" xlink:to="lab_us-gaap_OtherNoncashIncomeExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_2d61a772-f7c6-4663-8ab7-828016744864_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Purchase of available for sale investments</link:label>
    <link:label id="lab_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payments to Acquire Debt Securities, Available-for-Sale</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:to="lab_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements_c38b3660-48b5-4dad-b128-f5e83f31972b_terseLabel_en-US" xlink:label="lab_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt securities, available for sale, cumulative amount advanced under subscription agreements</link:label>
    <link:label id="lab_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements_label_en-US" xlink:label="lab_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Securities, Available For Sale, Cumulative Amount Advanced Under Subscription Agreements</link:label>
    <link:label id="lab_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements_documentation_en-US" xlink:label="lab_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Securities, Available For Sale, Cumulative Amount Advanced Under Subscription Agreements</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements" xlink:href="iclr-20231231.xsd#iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements" xlink:to="lab_iclr_DebtSecuritiesAvailableForSaleCumulativeAmountAdvancedUnderSubscriptionAgreements" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessAcquisitionAxis_7d8ce060-9654-4877-974c-946baa866055_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Acquisition [Axis]</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionAxis_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Acquisition [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessAcquisitionAxis" xlink:to="lab_us-gaap_BusinessAcquisitionAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeTable_eed75769-fcfe-4fba-a2e8-ac84824efe1f_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative [Table]</link:label>
    <link:label id="lab_us-gaap_DerivativeTable_label_en-US" xlink:label="lab_us-gaap_DerivativeTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeTable" xlink:to="lab_us-gaap_DerivativeTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_VariableRateAxis_f8b33ea1-e544-4191-b6cb-08c6a78573d4_terseLabel_en-US" xlink:label="lab_us-gaap_VariableRateAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Variable Rate [Axis]</link:label>
    <link:label id="lab_us-gaap_VariableRateAxis_label_en-US" xlink:label="lab_us-gaap_VariableRateAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Variable Rate [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_VariableRateAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_VariableRateAxis" xlink:to="lab_us-gaap_VariableRateAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CostsAndExpensesAbstract_a7aa955e-acb8-4def-9b0d-4b7ae06755aa_terseLabel_en-US" xlink:label="lab_us-gaap_CostsAndExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Costs and expenses:</link:label>
    <link:label id="lab_us-gaap_CostsAndExpensesAbstract_label_en-US" xlink:label="lab_us-gaap_CostsAndExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Costs and Expenses [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpensesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostsAndExpensesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostsAndExpensesAbstract" xlink:to="lab_us-gaap_CostsAndExpensesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_e65010dc-bff0-415f-8e2a-42fa1630d972_negatedLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Canceled/expired (in shares)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_Security12bTitle_869e0af3-1a59-4894-88ce-29cc1d07ef4a_terseLabel_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Title of 12(b) Security</link:label>
    <link:label id="lab_dei_Security12bTitle_label_en-US" xlink:label="lab_dei_Security12bTitle" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Title of 12(b) Security</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_Security12bTitle" xlink:to="lab_dei_Security12bTitle" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestructuringCostAndReserveLineItems_27a4dc4a-7d43-4eb1-bb5f-f08cb2e962c0_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCostAndReserveLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring Cost and Reserve [Line Items]</link:label>
    <link:label id="lab_us-gaap_RestructuringCostAndReserveLineItems_label_en-US" xlink:label="lab_us-gaap_RestructuringCostAndReserveLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring Cost and Reserve [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems" xlink:to="lab_us-gaap_RestructuringCostAndReserveLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_594e9928-ecbf-4a83-b34d-6760f33f9deb_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other non-current liabilities</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_LeaseLiabilityMember_7ecf79f0-325b-43dc-9225-7a9726f8b60b_terseLabel_en-US" xlink:label="lab_iclr_LeaseLiabilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Lease Liability</link:label>
    <link:label id="lab_iclr_LeaseLiabilityMember_label_en-US" xlink:label="lab_iclr_LeaseLiabilityMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Lease Liability [Member]</link:label>
    <link:label id="lab_iclr_LeaseLiabilityMember_documentation_en-US" xlink:label="lab_iclr_LeaseLiabilityMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Lease Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_LeaseLiabilityMember" xlink:href="iclr-20231231.xsd#iclr_LeaseLiabilityMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_LeaseLiabilityMember" xlink:to="lab_iclr_LeaseLiabilityMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DefinedBenefitPlanActuarialGainLoss_af4aa525-7f58-4e63-91e9-757dbb208da0_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Actuarial gain</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanActuarialGainLoss_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:to="lab_us-gaap_DefinedBenefitPlanActuarialGainLoss" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RelatedPartyDomain_bf0e57e6-e7b4-4175-b706-f2a30711c1fa_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Related Party [Domain]</link:label>
    <link:label id="lab_us-gaap_RelatedPartyDomain_label_en-US" xlink:label="lab_us-gaap_RelatedPartyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Related Party, Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RelatedPartyDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RelatedPartyDomain" xlink:to="lab_us-gaap_RelatedPartyDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubleaseIncome_913439cf-27d3-473c-bd23-0918022bbebd_negatedLabel_en-US" xlink:label="lab_us-gaap_SubleaseIncome" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income from sub-leases</link:label>
    <link:label id="lab_us-gaap_SubleaseIncome_label_en-US" xlink:label="lab_us-gaap_SubleaseIncome" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Sublease Income</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubleaseIncome"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubleaseIncome" xlink:to="lab_us-gaap_SubleaseIncome" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessCombinationDisclosureTextBlock_c233e731-1da2-4c99-958d-a2e7e8ae68e1_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combinations</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationDisclosureTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:to="lab_us-gaap_BusinessCombinationDisclosureTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_AdvancePaymentsNettedAgainstUnbilledContractsReceivable_ee0088fd-197a-4d1f-b4dd-c7500616255b_terseLabel_en-US" xlink:label="lab_iclr_AdvancePaymentsNettedAgainstUnbilledContractsReceivable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net balance</link:label>
    <link:label id="lab_iclr_AdvancePaymentsNettedAgainstUnbilledContractsReceivable_label_en-US" xlink:label="lab_iclr_AdvancePaymentsNettedAgainstUnbilledContractsReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Advance Payments Netted Against Unbilled Contracts Receivable</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_b0cc7c72-81b2-4a54-ad32-f9d71c00259c_periodStartLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Outstanding at beginning of period (USD per share)</link:label>
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    <link:label id="lab_us-gaap_IncomeTaxDisclosureAbstract_3cc27d3b-2b0c-4373-91bc-79dfaa48c5e9_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Tax Disclosure [Abstract]</link:label>
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    <link:label id="lab_us-gaap_DerivativeFixedInterestRate_ec845e68-044e-4d91-a23c-89de082f4dc9_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeFixedInterestRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, fixed interest rate</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid_b6f0f843-2f74-4a67-ad2d-39b539c7392e_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentPeriodicPaymentTermsBalloonPaymentToBePaid" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accelerated charge on repayments</link:label>
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    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_396ef255-47bb-4413-b8db-94272158bb91_terseLabel_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Payment Arrangement [Abstract]</link:label>
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    <link:label id="lab_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_0bb82ab3-5f09-4624-af3b-05e767f60430_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillForeignCurrencyTranslationGainLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Foreign exchange movement</link:label>
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    <link:label id="lab_us-gaap_LeaseCost_33a3a1d7-4415-409d-9dad-240b4cad45e8_totalLabel_en-US" xlink:label="lab_us-gaap_LeaseCost" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net operating lease costs</link:label>
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    <link:label id="lab_us-gaap_OtherComprehensiveIncomeMember_84aa0f16-a77e-4d7a-85b9-1b4134a76b36_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Comprehensive Income</link:label>
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    <link:label id="lab_us-gaap_DisaggregationOfRevenueTable_cb76fcf0-dcd1-43c2-a098-4291a676d589_terseLabel_en-US" xlink:label="lab_us-gaap_DisaggregationOfRevenueTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Disaggregation of Revenue [Table]</link:label>
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    <link:label id="lab_iclr_AccumulatedOtherComprehensiveIncomeLossTextBlock_8408ac13-d067-44d3-931e-b707934e89d0_terseLabel_en-US" xlink:label="lab_iclr_AccumulatedOtherComprehensiveIncomeLossTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated Other Comprehensive Loss</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanInterestCost_e96c525d-24de-429c-b293-81c71fb751f2_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanInterestCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest cost</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanInterestCost_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanInterestCost" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Interest Cost</link:label>
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    <link:label id="lab_dei_AuditorLocation_fd6e2743-9774-4dd2-88ae-af0f6bed6fea_terseLabel_en-US" xlink:label="lab_dei_AuditorLocation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Auditor location</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanDisclosureLineItems_8ba715c3-e64b-4e69-b4fb-0698c5c8f54f_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan Disclosure [Line Items]</link:label>
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    <link:label id="lab_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock_bd712c01-e100-4076-b698-bc393272ba89_terseLabel_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Employee Benefits</link:label>
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    <link:label id="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition_192582f6-7ee3-4b04-89ed-e80aea4e719b_terseLabel_en-US" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Replacement share-based awards issued to acquiree employees</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentAnnualPrincipalPayment_793c3b58-914c-4765-a897-80a58dc44cdb_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentAnnualPrincipalPayment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total</link:label>
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    <link:label id="lab_us-gaap_DatabasesMember_660d6b73-ca14-49c9-bf86-ba7f88acba8a_terseLabel_en-US" xlink:label="lab_us-gaap_DatabasesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Patient database</link:label>
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    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxAssets_label_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentDeferredTaxAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Assets</link:label>
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    <link:label id="lab_us-gaap_RelatedPartyTransactionDomain_a689fd92-c679-4c87-9fd1-9866deaf4852_terseLabel_en-US" xlink:label="lab_us-gaap_RelatedPartyTransactionDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Related Party Transaction [Domain]</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_7f60be0e-4fc1-4145-aa9a-5fa1c69f54f0_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2025</link:label>
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    <link:label id="lab_us-gaap_RetirementPlanNameDomain_3c0b65aa-0b3d-4b47-b27a-cc61e65d53dc_terseLabel_en-US" xlink:label="lab_us-gaap_RetirementPlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Retirement Plan Name [Domain]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive"/>
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    <link:label id="lab_country_IE_00f8652a-c78c-4b03-af63-10f787ed649b_terseLabel_en-US" xlink:label="lab_country_IE" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Ireland</link:label>
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    <link:label id="lab_iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses_b54e4117-2850-46ff-8625-f2bf6fedf7a9_terseLabel_en-US" xlink:label="lab_iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Amounts due to third parties for reimbursable expenses</link:label>
    <link:label id="lab_iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses_label_en-US" xlink:label="lab_iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Liabilities, Amount Payable To Third Parties For Reimbursable Expenses</link:label>
    <link:label id="lab_iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses_documentation_en-US" xlink:label="lab_iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Liabilities, Amount Payable To Third Parties For Reimbursable Expenses</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses" xlink:href="iclr-20231231.xsd#iclr_OtherLiabilitiesAmountPayableToThirdPartiesForReimbursableExpenses"/>
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    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_41ad92ac-dfd7-4a80-8d12-b073294ceb7e_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net cash provided by operating activities</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net Cash Provided by (Used in) Operating Activities</link:label>
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    <link:label id="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_a829ae57-ef63-469f-bf2c-6877090d621a_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Future Intangible Asset Amortization Expense</link:label>
    <link:label id="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock"/>
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    <link:label id="lab_iclr_AfimmuneLimitedMember_7024e6ca-cc3a-4ca4-b85a-ed293c7938e8_terseLabel_en-US" xlink:label="lab_iclr_AfimmuneLimitedMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Afimmune Limited</link:label>
    <link:label id="lab_iclr_AfimmuneLimitedMember_label_en-US" xlink:label="lab_iclr_AfimmuneLimitedMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Afimmune Limited [Member]</link:label>
    <link:label id="lab_iclr_AfimmuneLimitedMember_documentation_en-US" xlink:label="lab_iclr_AfimmuneLimitedMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Afimmune Limited</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_AfimmuneLimitedMember" xlink:href="iclr-20231231.xsd#iclr_AfimmuneLimitedMember"/>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_0bf5169d-9da0-4d79-8ba8-c4d9789cdc86_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Prior service cost</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Amortization of Prior Service Cost (Credit)</link:label>
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    <link:label id="lab_us-gaap_LinesOfCreditCurrent_b8871f80-21c3-4aad-96d2-02c05e1fd927_terseLabel_en-US" xlink:label="lab_us-gaap_LinesOfCreditCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Current bank credit lines and loan facilities (Note 13)</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LinesOfCreditCurrent" xlink:to="lab_us-gaap_LinesOfCreditCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DepreciationDepletionAndAmortization_77ed0ab3-2959-4b71-8828-284cad1c6a4a_terseLabel_en-US" xlink:label="lab_us-gaap_DepreciationDepletionAndAmortization" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Depreciation and amortization expense</link:label>
    <link:label id="lab_us-gaap_DepreciationDepletionAndAmortization_label_en-US" xlink:label="lab_us-gaap_DepreciationDepletionAndAmortization" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Depreciation, Depletion and Amortization</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
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    <link:label id="lab_us-gaap_FurnitureAndFixturesMember_2c96b5c2-7018-41e3-a110-d5ad7633fb57_terseLabel_en-US" xlink:label="lab_us-gaap_FurnitureAndFixturesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Office furniture and fixtures</link:label>
    <link:label id="lab_us-gaap_FurnitureAndFixturesMember_label_en-US" xlink:label="lab_us-gaap_FurnitureAndFixturesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Furniture and Fixtures [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FurnitureAndFixturesMember"/>
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    <link:label id="lab_iclr_AwardDateAllYearsExcluding2018Member_ec032826-cd20-4702-bda4-9d1247078326_terseLabel_en-US" xlink:label="lab_iclr_AwardDateAllYearsExcluding2018Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Award date, prior to 2018</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_iclr_AwardDateAllYearsExcluding2018Member" xlink:href="iclr-20231231.xsd#iclr_AwardDateAllYearsExcluding2018Member"/>
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    <link:label id="lab_us-gaap_BusinessCombinationAndAssetAcquisitionAbstract_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationAndAssetAcquisitionAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination and Asset Acquisition [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAndAssetAcquisitionAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationAndAssetAcquisitionAbstract"/>
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    <link:label id="lab_iclr_EffectiveIncomeTaxRateReconciliationDeferredTaxProvisionOnUnrepatriatedEarningsAmount_87ede9e6-cb41-4105-a8f9-3def979b6ac5_terseLabel_en-US" xlink:label="lab_iclr_EffectiveIncomeTaxRateReconciliationDeferredTaxProvisionOnUnrepatriatedEarningsAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Investor tax expense on foreign subsidiary earnings</link:label>
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    <link:label id="lab_us-gaap_NoncurrentAssets_2781f233-6d41-40f8-8e6e-d93a92ba8d91_terseLabel_en-US" xlink:label="lab_us-gaap_NoncurrentAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-lived assets</link:label>
    <link:label id="lab_us-gaap_NoncurrentAssets_label_en-US" xlink:label="lab_us-gaap_NoncurrentAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-Lived Assets</link:label>
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    <link:label id="lab_us-gaap_GoodwillImpairmentLoss_ad643560-36a3-428b-8d67-9d7e9a293baf_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Goodwill impairment charge</link:label>
    <link:label id="lab_us-gaap_GoodwillImpairmentLoss_label_en-US" xlink:label="lab_us-gaap_GoodwillImpairmentLoss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Goodwill, Impairment Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GoodwillImpairmentLoss"/>
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    <link:label id="lab_dei_EntityNumberOfEmployees_8b4a1b12-b2e9-4308-afed-cd576c8a9a13_terseLabel_en-US" xlink:label="lab_dei_EntityNumberOfEmployees" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Number of employees</link:label>
    <link:label id="lab_dei_EntityNumberOfEmployees_label_en-US" xlink:label="lab_dei_EntityNumberOfEmployees" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Number of Employees</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityNumberOfEmployees" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityNumberOfEmployees"/>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentNet_4d680f92-7b65-4284-8266-4231e7519ca9_verboseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Property, plant and equipment, net (Note 9)</link:label>
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    <link:label id="lab_dei_BusinessContactMember_23e085c4-7533-4df5-b564-eee401f5331f_terseLabel_en-US" xlink:label="lab_dei_BusinessContactMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Contact</link:label>
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    <link:label id="lab_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_214f8078-cb1c-452c-9654-3e5bec3c1fc8_terseLabel_en-US" xlink:label="lab_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table]</link:label>
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    <link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_446ffa70-1a6c-441d-80dc-c4e918801340_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Statement of Cash Flows [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfCashFlowsAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Statement of Cash Flows [Abstract]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract" xlink:to="lab_us-gaap_StatementOfCashFlowsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligation_226c08b3-9ca0-4d50-b935-e770dc783dc2_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Non-current other liabilities (note 16)</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligation_dd975b2e-0063-48b4-b8f3-c28b5981ce67_periodStartLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Benefit obligation at beginning of year</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligation_336db9c3-e9d5-4a75-9f58-1cefd6a4fdbb_periodEndLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Benefit obligation at end of year</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligation_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Benefit Obligation</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:to="lab_us-gaap_DefinedBenefitPlanBenefitObligation" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsAbstract_dcc61efe-525b-4198-b133-224e942dd871_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">ASSETS</link:label>
    <link:label id="lab_us-gaap_AssetsAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assets [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="lab_us-gaap_AssetsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_4c934b12-14f6-4a5c-8c14-5c960444b469_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2026</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Expected Future Benefit Payment, Year Three</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
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    <link:label id="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_0b187889-1456-4543-ac2d-cb0bf11e3a52_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Amounts charged/(credited)</link:label>
    <link:label id="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_label_en-US" xlink:label="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gain (Loss), Foreign Currency Transaction, before Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:to="lab_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_12155d83-e7df-42a4-8e39-06d693962c16_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Derivative Instruments in Statement of Financial Position, Fair Value</link:label>
    <link:label id="lab_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock"/>
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    <link:label id="lab_iclr_DeferredTaxAssetsTaxDeferredExpenseOtherLiabilities_371c69af-2399-4a5d-9d6f-6608cf54d536_terseLabel_en-US" xlink:label="lab_iclr_DeferredTaxAssetsTaxDeferredExpenseOtherLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other liabilities</link:label>
    <link:label id="lab_iclr_DeferredTaxAssetsTaxDeferredExpenseOtherLiabilities_label_en-US" xlink:label="lab_iclr_DeferredTaxAssetsTaxDeferredExpenseOtherLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Deferred Tax Assets, Tax Deferred Expense, Other Liabilities</link:label>
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    <link:label id="lab_us-gaap_DeferredTaxAssetsNetAbstract_c05b0a14-afcf-4384-b528-d16f3e29422a_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsNetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Deferred tax assets:</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetsNetAbstract_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsNetAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Deferred Tax Assets, Net [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsNetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredTaxAssetsNetAbstract"/>
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    <link:label id="lab_us-gaap_BilledContractReceivables_a9d02fb2-4a63-46e1-9c51-4499b58cd673_terseLabel_en-US" xlink:label="lab_us-gaap_BilledContractReceivables" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Billed services (accounts receivable)</link:label>
    <link:label id="lab_us-gaap_BilledContractReceivables_label_en-US" xlink:label="lab_us-gaap_BilledContractReceivables" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Billed Contracts Receivable</link:label>
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    <link:label id="lab_us-gaap_LiabilitiesAbstract_1394586e-1c3d-4f80-b086-84290fe12859_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Liabilities:</link:label>
    <link:label id="lab_us-gaap_LiabilitiesAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Liabilities [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="lab_us-gaap_LiabilitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities_a222347d-ba79-4e19-8fca-f9566383607a_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net cash (used in)/provided by financing activities</link:label>
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    <link:label id="lab_us-gaap_RetirementPlanTypeAxis_85722991-c461-4979-a7ae-0b5ade55de8d_terseLabel_en-US" xlink:label="lab_us-gaap_RetirementPlanTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Retirement Plan Type [Axis]</link:label>
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    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_acf9abdd-f312-4423-940c-e1dfe69e2cf3_terseLabel_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Commitments and Contingencies</link:label>
    <link:label id="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_label_en-US" xlink:label="lab_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Commitments and Contingencies Disclosure [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
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    <link:label id="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_5ca68b12-182a-42ef-8b5a-9e1c2dea390e_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Percentage of share capital acquired</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_525e3b33-edb5-4a19-baae-200342f4861c_verboseLabel_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Percentage of share capital acquired (in percent)</link:label>
    <link:label id="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_label_en-US" xlink:label="lab_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Acquisition, Percentage of Voting Interests Acquired</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
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    <link:label id="lab_us-gaap_ContractWithCustomerAssetGrossCurrent_ff097af9-db18-4b00-8942-91d24fe97e66_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetGrossCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Unbilled revenue (Note 4)</link:label>
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    <link:label id="lab_us-gaap_ContractWithCustomerAssetGrossCurrent_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetGrossCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Contract with Customer, Asset, before Allowance for Credit Loss, Current</link:label>
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    <link:label id="lab_us-gaap_RetainedEarningsMember_86defcba-0a36-4612-9f9e-54daee77779e_terseLabel_en-US" xlink:label="lab_us-gaap_RetainedEarningsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Retained Earnings</link:label>
    <link:label id="lab_us-gaap_RetainedEarningsMember_label_en-US" xlink:label="lab_us-gaap_RetainedEarningsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Retained Earnings [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_5696dc0f-460e-49f8-b5dc-90f482be2ab6_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net loss that will be amortized</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear"/>
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    <link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_608f9e4a-53d0-48cd-b478-b898b022ac30_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other current assets</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_53ef2c70-e670-478d-af69-9373813855e6_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Foreign currency exchange rate changes</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation"/>
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    <link:label id="lab_us-gaap_EarningsPerShareBasic_22f304d8-b62f-4f48-9218-0a0205fe3c3e_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Basic (USD per share)</link:label>
    <link:label id="lab_us-gaap_EarningsPerShareBasic_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareBasic" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Earnings Per Share, Basic</link:label>
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    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_abad6006-9610-4a1f-a17c-1d2141630b83_terseLabel_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_label_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountingPoliciesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountingPoliciesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountingPoliciesAbstract" xlink:to="lab_us-gaap_AccountingPoliciesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ClassOfTreasuryStockTable_7278c878-70fb-43a3-addf-4a8badaf75e3_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfTreasuryStockTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Treasury Stock [Table]</link:label>
    <link:label id="lab_us-gaap_ClassOfTreasuryStockTable_label_en-US" xlink:label="lab_us-gaap_ClassOfTreasuryStockTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Treasury Stock [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfTreasuryStockTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ClassOfTreasuryStockTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfTreasuryStockTable" xlink:to="lab_us-gaap_ClassOfTreasuryStockTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestructuringCosts_bf8b1213-de74-4eae-a7fd-56bc41d17f01_verboseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCosts" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring (Note 19)</link:label>
    <link:label id="lab_us-gaap_RestructuringCosts_81e2790c-e380-4f99-812c-51262a0b00b9_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring charges</link:label>
    <link:label id="lab_us-gaap_RestructuringCosts_label_en-US" xlink:label="lab_us-gaap_RestructuringCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringCosts"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestructuringCosts" xlink:to="lab_us-gaap_RestructuringCosts" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_PRASwitzerlandAGPensionPlanMember_81b43c5a-7211-4ef9-af3c-e2ada0979a10_terseLabel_en-US" xlink:label="lab_iclr_PRASwitzerlandAGPensionPlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">PRA Switzerland AG pension plan</link:label>
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    <link:label id="lab_iclr_PRASwitzerlandAGPensionPlanMember_documentation_en-US" xlink:label="lab_iclr_PRASwitzerlandAGPensionPlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">PRA Switzerland AG Pension Plan</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_8692f02f-7d19-41d1-a73d-afbc7054b721_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Fair value of plan assets</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_137c110b-d6f5-43c2-acc3-22fe74174ef6_periodStartLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Fair value of plan assets at beginning of year</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_241ea058-8838-49f1-933f-5c84bff6ded8_periodEndLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Fair value of plan assets at end of year</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:to="lab_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxesReceivableNoncurrent_1f452912-f126-4710-95d2-8ef0798f13a2_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxesReceivableNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income taxes receivable</link:label>
    <link:label id="lab_us-gaap_IncomeTaxesReceivableNoncurrent_label_en-US" xlink:label="lab_us-gaap_IncomeTaxesReceivableNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Taxes Receivable, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesReceivableNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxesReceivableNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxesReceivableNoncurrent" xlink:to="lab_us-gaap_IncomeTaxesReceivableNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_d31d5c6c-cb6b-4c47-9d08-3be73dec5d5f_negatedLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Benefits paid</link:label>
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    <link:label id="lab_us-gaap_ConsolidationPolicyTextBlock_d259a7e3-7da9-434c-ab73-4f654e9d864d_terseLabel_en-US" xlink:label="lab_us-gaap_ConsolidationPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Basis of Consolidation</link:label>
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    <link:label id="lab_us-gaap_GoodwillPurchaseAccountingAdjustments_c05925f7-b096-4499-b2a7-b1616e75affd_terseLabel_en-US" xlink:label="lab_us-gaap_GoodwillPurchaseAccountingAdjustments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Prior period acquisition (note 6)</link:label>
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    <link:label id="lab_us-gaap_TechnologyBasedIntangibleAssetsMember_e01f41bb-b96a-4bd8-a787-8e66675d3659_terseLabel_en-US" xlink:label="lab_us-gaap_TechnologyBasedIntangibleAssetsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Technology assets</link:label>
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    <link:label id="lab_us-gaap_RepaymentsOfLinesOfCredit_406e7460-bb26-4cee-8915-09f293a72d98_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfLinesOfCredit" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Repayment of credit lines and facilities</link:label>
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    <link:label id="lab_dei_DocumentFinStmtErrorCorrectionFlag_d0a7fb9d-1cb9-4c60-9428-ed18bf7dfef3_terseLabel_en-US" xlink:label="lab_dei_DocumentFinStmtErrorCorrectionFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Financial Statement Error Correction [Flag]</link:label>
    <link:label id="lab_dei_DocumentFinStmtErrorCorrectionFlag_label_en-US" xlink:label="lab_dei_DocumentFinStmtErrorCorrectionFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Financial Statement Error Correction [Flag]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFinStmtErrorCorrectionFlag" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentFinStmtErrorCorrectionFlag"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentFinStmtErrorCorrectionFlag" xlink:to="lab_dei_DocumentFinStmtErrorCorrectionFlag" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_RestOfEuropeMember_a406d6b6-b36e-45ea-b8fd-cedd22e5ac78_terseLabel_en-US" xlink:label="lab_iclr_RestOfEuropeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Rest of Europe</link:label>
    <link:label id="lab_iclr_RestOfEuropeMember_label_en-US" xlink:label="lab_iclr_RestOfEuropeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Rest Of Europe [Member]</link:label>
    <link:label id="lab_iclr_RestOfEuropeMember_documentation_en-US" xlink:label="lab_iclr_RestOfEuropeMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Rest Of Europe [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_RestOfEuropeMember" xlink:href="iclr-20231231.xsd#iclr_RestOfEuropeMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_RestOfEuropeMember" xlink:to="lab_iclr_RestOfEuropeMember" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_InterestExpenseCreditOther_f4726b13-7f37-4f29-a3f7-b9333978fd16_terseLabel_en-US" xlink:label="lab_iclr_InterestExpenseCreditOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other financing costs</link:label>
    <link:label id="lab_iclr_InterestExpenseCreditOther_label_en-US" xlink:label="lab_iclr_InterestExpenseCreditOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest Expense (Credit), Other</link:label>
    <link:label id="lab_iclr_InterestExpenseCreditOther_documentation_en-US" xlink:label="lab_iclr_InterestExpenseCreditOther" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest Expense (Credit), Other</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_InterestExpenseCreditOther" xlink:href="iclr-20231231.xsd#iclr_InterestExpenseCreditOther"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_InterestExpenseCreditOther" xlink:to="lab_iclr_InterestExpenseCreditOther" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_e299649b-314b-4f3f-b24a-d3dc36ddb91c_negatedLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Forfeited (in shares)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_RestructuringReserveandOtherLiabilitiesCurrent_3501397a-f3bb-456a-9bee-7cd0667820d4_terseLabel_en-US" xlink:label="lab_iclr_RestructuringReserveandOtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring liabilities</link:label>
    <link:label id="lab_iclr_RestructuringReserveandOtherLiabilitiesCurrent_label_en-US" xlink:label="lab_iclr_RestructuringReserveandOtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring Reserve and Other Liabilities, Current</link:label>
    <link:label id="lab_iclr_RestructuringReserveandOtherLiabilitiesCurrent_documentation_en-US" xlink:label="lab_iclr_RestructuringReserveandOtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring Reserve and Other Liabilities, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_RestructuringReserveandOtherLiabilitiesCurrent" xlink:href="iclr-20231231.xsd#iclr_RestructuringReserveandOtherLiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_RestructuringReserveandOtherLiabilitiesCurrent" xlink:to="lab_iclr_RestructuringReserveandOtherLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember_d789fe36-b577-496a-99e2-a6a40fca6d66_terseLabel_en-US" xlink:label="lab_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior secured credit facility and senior secured notes</link:label>
    <link:label id="lab_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember_label_en-US" xlink:label="lab_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Secured Credit Facility And Senior Secured Notes [Member]</link:label>
    <link:label id="lab_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember_documentation_en-US" xlink:label="lab_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Secured Credit Facility And Senior Secured Notes</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember" xlink:href="iclr-20231231.xsd#iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember" xlink:to="lab_iclr_SeniorSecuredCreditFacilityAndSeniorSecuredNotesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable_5321e34e-851b-4c3d-9483-2e7099733802_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Allowance for credit losses (note 5)</link:label>
    <link:label id="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable_f10afa1f-8b4e-4a9d-85de-1cf7c61664a7_periodStartLabel_en-US" xlink:label="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Opening provision</link:label>
    <link:label id="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable_5a2068d8-2bd5-4101-b768-4f786369b94b_periodEndLabel_en-US" xlink:label="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Closing provision</link:label>
    <link:label id="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable_label_en-US" xlink:label="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts Receivable, Allowance for Credit Loss</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="lab_us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestructuringReserveCurrent_1edd6358-89d6-4624-bcf0-6ec3f1f6a69d_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringReserveCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring reserve, current</link:label>
    <link:label id="lab_us-gaap_RestructuringReserveCurrent_label_en-US" xlink:label="lab_us-gaap_RestructuringReserveCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restructuring Reserve, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RestructuringReserveCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestructuringReserveCurrent" xlink:to="lab_us-gaap_RestructuringReserveCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_dbd27eb2-8d0d-42b3-9db0-46619583f3fc_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2024</link:label>
    <link:label id="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_label_en-US" xlink:label="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-Term Debt, Maturity, Year One</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="lab_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f0f583f6-7fc4-4719-9ae6-05bed2be2c82_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
    <link:label id="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_label_en-US" xlink:label="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Segment Reporting Information, by Segment [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="lab_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets_42551bf1-a171-40ac-a096-a021d168142f_terseLabel_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other assets</link:label>
    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets_label_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets</link:label>
    <link:label id="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets_documentation_en-US" xlink:label="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" xlink:href="iclr-20231231.xsd#iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" xlink:to="lab_iclr_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentOtherAssets" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MachineryAndEquipmentGross_ccb6e64f-d531-4d71-92e0-e7a71e220b83_terseLabel_en-US" xlink:label="lab_us-gaap_MachineryAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Laboratory equipment</link:label>
    <link:label id="lab_us-gaap_MachineryAndEquipmentGross_label_en-US" xlink:label="lab_us-gaap_MachineryAndEquipmentGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Machinery and Equipment, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentGross" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MachineryAndEquipmentGross"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MachineryAndEquipmentGross" xlink:to="lab_us-gaap_MachineryAndEquipmentGross" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_d6f384f2-4f34-4d19-a03b-d1f8f572a518_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Issue of shares associated with a business combination (in shares)</link:label>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Stock Issued During Period, Shares, Acquisitions</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_ff72a7fc-dc22-4dee-a417-a29e930ffc5a_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Maximum range exercise price (USD per share)</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:to="lab_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentPeriodEndDate_baa4c424-0583-4e53-b3ce-9d29ad28974f_terseLabel_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Period End Date</link:label>
    <link:label id="lab_dei_DocumentPeriodEndDate_label_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Period End Date</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
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    <link:label id="lab_us-gaap_AmortizationOfDeferredHedgeGains_cb6aa36a-2768-4a51-8b83-625d63a0baab_terseLabel_en-US" xlink:label="lab_us-gaap_AmortizationOfDeferredHedgeGains" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Charge on cash flow hedge</link:label>
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    <link:label id="lab_iclr_OtherRetirementPlansMember_e1b1351a-c46f-48f3-8bc3-c72bb008593c_terseLabel_en-US" xlink:label="lab_iclr_OtherRetirementPlansMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other retirement plans</link:label>
    <link:label id="lab_iclr_OtherRetirementPlansMember_label_en-US" xlink:label="lab_iclr_OtherRetirementPlansMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Retirement Plans [Member]</link:label>
    <link:label id="lab_iclr_OtherRetirementPlansMember_documentation_en-US" xlink:label="lab_iclr_OtherRetirementPlansMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Retirement Plans</link:label>
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    <link:label id="lab_us-gaap_CreditFacilityDomain_3c8fdfd9-6865-45b8-bfc8-77da275b45a5_terseLabel_en-US" xlink:label="lab_us-gaap_CreditFacilityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Credit Facility [Domain]</link:label>
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    <link:label id="lab_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_e4e21936-678b-45cd-8e9b-a4834a7914e5_negatedLabel_en-US" xlink:label="lab_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Repurchase of ordinary shares (in shares)</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_0ae5c46e-0c98-49a9-adbd-cb3e43cd74fa_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Basis spread on variable rate (in percent)</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife_dcaaa905-f55f-48bb-bb34-bcd8ca1d9edf_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Estimated useful lives</link:label>
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    <link:label id="lab_iclr_BusinessCombinationConsiderationTransferredCashPaymentToShareholdersPerShareHeld_a4d4076c-fc42-48b4-856c-145b271f6675_terseLabel_en-US" xlink:label="lab_iclr_BusinessCombinationConsiderationTransferredCashPaymentToShareholdersPerShareHeld" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business acquisition, share price (in USD per share)</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_00bdb7ee-b915-4c4b-9e7a-dffef79c5d5a_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Discount rate</link:label>
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    <link:label id="lab_iclr_The2020LegacyPRAPlanMember_35710d0b-ff3b-43b3-9242-64f2695fa3ab_terseLabel_en-US" xlink:label="lab_iclr_The2020LegacyPRAPlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">The 2020 Legacy PRA Plan</link:label>
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    <link:label id="lab_iclr_The2020LegacyPRAPlanMember_documentation_en-US" xlink:label="lab_iclr_The2020LegacyPRAPlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">The 2020 Legacy PRA Plan</link:label>
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    <link:label id="lab_iclr_ReconciliationOfProvisionOfIncomeTaxesLineItems_806df5db-679a-4e8f-ae53-3cf087c8d026_terseLabel_en-US" xlink:label="lab_iclr_ReconciliationOfProvisionOfIncomeTaxesLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Reconciliation of Provision of Income Taxes [Line Items]</link:label>
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    <link:label id="lab_us-gaap_DerivativeLiabilityNoncurrentStatementOfFinancialPositionExtensibleEnumeration_8ca40fb5-8b4a-49a6-b53a-3e335b897a7e_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilityNoncurrentStatementOfFinancialPositionExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]</link:label>
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    <link:label id="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock_7688518f-c576-4bc0-8a76-7eaae3fe2f2b_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetAndLiabilityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Contracts with Customers, Asset and Liabilities</link:label>
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    <link:label id="lab_us-gaap_OtherNoncurrentLiabilitiesTableTextBlock_a53c1180-d92d-479e-a84c-485bd1568a87_terseLabel_en-US" xlink:label="lab_us-gaap_OtherNoncurrentLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Non-current other liabilities</link:label>
    <link:label id="lab_us-gaap_OtherNoncurrentLiabilitiesTableTextBlock_label_en-US" xlink:label="lab_us-gaap_OtherNoncurrentLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Noncurrent Liabilities [Table Text Block]</link:label>
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    <link:label id="lab_us-gaap_VehiclesMember_1b5ea93b-69b2-44cf-805a-3eb3834a92f9_terseLabel_en-US" xlink:label="lab_us-gaap_VehiclesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Motor vehicles</link:label>
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    <link:label id="lab_srt_StatementGeographicalAxis_9f5387a8-68e2-4d70-bb70-afa0c79bf034_terseLabel_en-US" xlink:label="lab_srt_StatementGeographicalAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Geographical</link:label>
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    <link:label id="lab_us-gaap_ForeignPlanMember_460e0afe-f2c3-4122-9daa-62bb0b9c336e_terseLabel_en-US" xlink:label="lab_us-gaap_ForeignPlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Foreign Plan</link:label>
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    <link:label id="lab_us-gaap_IncomeTaxDisclosureTextBlock_3862c9ef-8dfd-4788-bad5-d0433903c65f_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Taxes</link:label>
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    <link:label id="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_86b87717-f052-490d-9976-cfa799c90830_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Unearned revenue</link:label>
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    <link:label id="lab_us-gaap_OtherLiabilitiesTableTextBlock_0e4e8984-1a7a-4eb3-b240-325820ebd786_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Other Liabilities</link:label>
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    <link:label id="lab_us-gaap_LongTermDebtFairValue_label_en-US" xlink:label="lab_us-gaap_LongTermDebtFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-Term Debt, Fair Value</link:label>
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    <link:label id="lab_us-gaap_NetIncomeLoss_2f0a627a-3f32-47cb-b049-a6a9a46ebaf2_totalLabel_en-US" xlink:label="lab_us-gaap_NetIncomeLoss" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net income</link:label>
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    <link:label id="lab_us-gaap_LiabilitiesCurrent_583bac96-2882-4ec4-ab3b-f0f308866185_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total current liabilities</link:label>
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    <link:label id="lab_us-gaap_DerivativeContractTypeDomain_e12e8fc3-f6c9-4a11-a70f-695e063667c2_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Contract [Domain]</link:label>
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    <link:label id="lab_us-gaap_LesseeOperatingLeasesTextBlock_595f1542-469b-42e5-af94-f98c5bdf24d6_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeasesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating Leases</link:label>
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    <link:label id="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_edda6f5a-376e-44bd-8703-a1eedb6ca656_terseLabel_en-US" xlink:label="lab_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Acquired Finite-Lived Intangible Assets [Line Items]</link:label>
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    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_283a0b02-4e78-4427-92e1-6c4c58ef7546_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">LIABILITIES AND SHAREHOLDERS&#8217; EQUITY</link:label>
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    <link:label id="lab_iclr_LongTermDebtCurrentMaturitiesGross_acd0e006-5c7b-40ac-95d4-ccd41a6fc7e4_negatedTerseLabel_en-US" xlink:label="lab_iclr_LongTermDebtCurrentMaturitiesGross" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Less current portion of debt</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_a7495cb5-c64e-4685-a810-74e471144fee_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Foreign currency exchange rate changes</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_iclr_OperatingIncomeByGeographyTableTextBlock" xlink:href="iclr-20231231.xsd#iclr_OperatingIncomeByGeographyTableTextBlock"/>
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    <link:label id="lab_iclr_OperatingIncomeLossBeforeRestructuringChargesTransactionAndIntegrationExpenses_94e1237c-9404-4dae-881e-f2c4593dc171_terseLabel_en-US" xlink:label="lab_iclr_OperatingIncomeLossBeforeRestructuringChargesTransactionAndIntegrationExpenses" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income from operations, excluding restructuring and other items</link:label>
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    <link:label id="lab_us-gaap_Goodwill_c16f94be-cedd-4292-8478-8b101b6c9b9d_verboseLabel_en-US" xlink:label="lab_us-gaap_Goodwill" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Goodwill (Note 10)</link:label>
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    <link:label id="lab_us-gaap_BuildingsAndImprovementsGross_4972cac4-45f9-4c5a-aeb2-1d83b9c1309d_terseLabel_en-US" xlink:label="lab_us-gaap_BuildingsAndImprovementsGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Buildings</link:label>
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    <link:label id="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember_575137b1-a49b-460b-a0d9-cc9b305e4440_terseLabel_en-US" xlink:label="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Selling, general and administrative</link:label>
    <link:label id="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember_label_en-US" xlink:label="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Selling, General and Administrative Expenses [Member]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:to="lab_us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseLiabilityNoncurrent_ca87a9b1-37a0-4953-b164-27a72f36fd8e_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Lease liabilities (Note 15)</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="lab_us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsToFundLongtermLoansToRelatedParties_8d1aaa79-b72f-429c-b93f-50aea306e080_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToFundLongtermLoansToRelatedParties" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Loan to equity method investment</link:label>
    <link:label id="lab_us-gaap_PaymentsToFundLongtermLoansToRelatedParties_label_en-US" xlink:label="lab_us-gaap_PaymentsToFundLongtermLoansToRelatedParties" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payments to Fund Long-Term Loans to Related Parties</link:label>
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    <link:label id="lab_us-gaap_PaymentsOfStockIssuanceCosts_1ce02fdd-2398-42a1-8261-78d9a1280ca0_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfStockIssuanceCosts" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share issue costs</link:label>
    <link:label id="lab_us-gaap_PaymentsOfStockIssuanceCosts_label_en-US" xlink:label="lab_us-gaap_PaymentsOfStockIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payments of Stock Issuance Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsOfStockIssuanceCosts"/>
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    <link:label id="lab_us-gaap_DebtInstrumentNameDomain_eca80510-1bbe-4c9b-8e1d-bb7f70ce4c61_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Name [Domain]</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentNameDomain_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Name [Domain]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="lab_us-gaap_DebtInstrumentNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings_a7f55a35-568f-4d5d-9f1a-d3fbad594b5c_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Investments in foreign subsidiaries</link:label>
    <link:label id="lab_us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings_label_en-US" xlink:label="lab_us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Deferred Tax Liabilities, Undistributed Foreign Earnings</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings"/>
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    <link:label id="lab_iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent_55031089-f195-47b1-9134-22d5d2f32e80_terseLabel_en-US" xlink:label="lab_iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Change in advance payments netted against unbilled contracts receivable (in percent)</link:label>
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    <link:label id="lab_iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent_documentation_en-US" xlink:label="lab_iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Change in Advance Payments Netted Against Unbilled Contracts Receivable, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent" xlink:href="iclr-20231231.xsd#iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent" xlink:to="lab_iclr_ChangeinAdvancePaymentsNettedAgainstUnbilledContractsReceivablePercent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeStatementLocationAxis_92dd1ced-de68-4e30-80e8-00d62d9d7224_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Statement Location [Axis]</link:label>
    <link:label id="lab_us-gaap_IncomeStatementLocationAxis_label_en-US" xlink:label="lab_us-gaap_IncomeStatementLocationAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Statement Location [Axis]</link:label>
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    <link:label id="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_6074df69-738a-4aaa-b83e-0c9cac274526_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Non-current other liabilities (note 16)</link:label>
    <link:label id="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_label_en-US" xlink:label="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Liability, Defined Benefit Plan, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:to="lab_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_a5eba0cb-6109-48b0-aa16-8a7ca4407d0d_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Less debt issuance costs and debt discount</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:to="lab_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock_c6cf6acd-aa3a-4905-9f5d-d8feecdee638_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Operating Lease Maturity</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LesseeOperatingLeaseLiabilityMaturityTableTextBlock"/>
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    <link:label id="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_027926b7-b087-455c-ab79-c853b47ef1ec_terseLabel_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Effect of dilutive share options and other awards outstanding under share based compensation programs (in shares)</link:label>
    <link:label id="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_label_en-US" xlink:label="lab_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Weighted Average Number of Shares Outstanding, Diluted, Adjustment</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_2071456a-eb60-4f2d-92d3-62fce09d566b_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward"/>
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    <link:label id="lab_us-gaap_RepaymentsOfSeniorDebt_9587f488-1af0-44d4-96fc-c7a69525b639_terseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfSeniorDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Repayment</link:label>
    <link:label id="lab_us-gaap_RepaymentsOfSeniorDebt_label_en-US" xlink:label="lab_us-gaap_RepaymentsOfSeniorDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Repayments of Senior Debt</link:label>
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    <link:label id="lab_srt_EuropeMember_113d1e97-b3ce-47bc-9c4f-a45cb4e67fac_terseLabel_en-US" xlink:label="lab_srt_EuropeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Europe</link:label>
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    <link:label id="lab_us-gaap_CashAndCashEquivalentsPolicyTextBlock_156534d1-e758-41d3-83e6-476a38c31eb6_terseLabel_en-US" xlink:label="lab_us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cash and Cash Equivalents</link:label>
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    <link:label id="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_ab408b03-220f-4573-8715-a0018e834dbb_negatedLabel_en-US" xlink:label="lab_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share issuance costs</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
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    <link:label id="lab_us-gaap_PayablesAndAccrualsAbstract_0dbc6b6e-ef5a-4141-a878-b652eba78fe2_terseLabel_en-US" xlink:label="lab_us-gaap_PayablesAndAccrualsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payables and Accruals [Abstract]</link:label>
    <link:label id="lab_us-gaap_PayablesAndAccrualsAbstract_label_en-US" xlink:label="lab_us-gaap_PayablesAndAccrualsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payables and Accruals [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PayablesAndAccrualsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PayablesAndAccrualsAbstract"/>
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    <link:label id="lab_us-gaap_LeaseCostTableTextBlock_b15e131d-499d-4f1a-9c1d-1e61cf58a082_terseLabel_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Lease Cost</link:label>
    <link:label id="lab_us-gaap_LeaseCostTableTextBlock_label_en-US" xlink:label="lab_us-gaap_LeaseCostTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Lease, Cost [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCostTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LeaseCostTableTextBlock"/>
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    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_e496fc73-612b-41d6-94fe-ee4adbd4b76f_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cash flows from investing activities:</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities [Abstract]</link:label>
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    <link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseOther_5d74f497-d65a-4fd6-93e4-994f04d4b95a_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseOther_label_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxDeferredExpenseOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Deferred Tax Assets, Tax Deferred Expense, Other</link:label>
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    <link:label id="lab_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Instruments and Hedging Activities Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract"/>
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    <link:label id="lab_us-gaap_PlanNameDomain_152849d9-4f18-4834-b29a-a5ac89e04005_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Plan Name [Domain]</link:label>
    <link:label id="lab_us-gaap_PlanNameDomain_label_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Plan Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PlanNameDomain"/>
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    <link:label id="lab_us-gaap_IncomeTaxesReceivable_fb634f48-e983-44a6-9ad7-c819079c3d96_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxesReceivable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income taxes receivable</link:label>
    <link:label id="lab_us-gaap_IncomeTaxesReceivable_label_en-US" xlink:label="lab_us-gaap_IncomeTaxesReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Taxes Receivable, Current</link:label>
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    <link:label id="lab_iclr_AuditInformationAbstract_label_en-US" xlink:label="lab_iclr_AuditInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Audit Information [Abstract]</link:label>
    <link:label id="lab_iclr_AuditInformationAbstract_documentation_en-US" xlink:label="lab_iclr_AuditInformationAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Audit Information</link:label>
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    <link:label id="lab_us-gaap_InterestExpense_fac5b8bc-8f9e-4c0a-8c81-dd72cf8af3db_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest expense (Note 13)</link:label>
    <link:label id="lab_us-gaap_InterestExpense_6307fecf-7df6-45d5-b534-e1f5c4401bd0_terseLabel_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total financing costs</link:label>
    <link:label id="lab_us-gaap_InterestExpense_36b12569-9905-486e-936b-650866491c01_totalLabel_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total financing costs</link:label>
    <link:label id="lab_us-gaap_InterestExpense_label_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_InterestExpense"/>
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    <link:label id="lab_us-gaap_GainsLossesOnExtinguishmentOfDebt_c9877bb4-9512-49ad-998f-1e20959d4068_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Loss on extinguishment of debt</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_075ca954-ad52-4518-a659-6c3bcbdfef50_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Ordinary shares which have been reserved for issuance (in shares)</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_ccd7ca58-1a1b-4630-84c6-fc7defd4434e_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Weighted average contractual term of options outstanding</link:label>
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    <link:label id="lab_us-gaap_OperatingLossCarryforwardsTable_cfa1a282-917b-4d7d-ac81-e6461e3e10da_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLossCarryforwardsTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating Loss Carryforwards [Table]</link:label>
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    <link:label id="lab_iclr_NumberOfLocations_aec0f660-8891-42cb-b189-d5b500887607_terseLabel_en-US" xlink:label="lab_iclr_NumberOfLocations" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Number of locations in which company operates</link:label>
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    <link:label id="lab_us-gaap_UseOfEstimates_aafec6de-13f4-400e-aae3-13c6d348a8c9_terseLabel_en-US" xlink:label="lab_us-gaap_UseOfEstimates" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Use of Estimates</link:label>
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    <link:label id="lab_us-gaap_LongtermDebtTypeDomain_fc90b655-d59f-4915-8783-d4fe837f0934_terseLabel_en-US" xlink:label="lab_us-gaap_LongtermDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-term Debt, Type [Domain]</link:label>
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    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_e5eda19f-3caa-4892-96d8-7937b14194aa_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Thereafter</link:label>
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    <link:label id="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax_10a09e0e-6fef-4293-b799-f7bb5b01a287_terseLabel_en-US" xlink:label="lab_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Alternative minimum tax credit carry forwards</link:label>
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    <link:label id="lab_us-gaap_OperatingLeaseCost_34d9a0e9-d452-4066-b975-57169606640b_terseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseCost" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating lease costs</link:label>
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    <link:label id="lab_us-gaap_SeveranceCosts1_3bb99a9e-f5d0-4220-831c-74ec7da200c2_terseLabel_en-US" xlink:label="lab_us-gaap_SeveranceCosts1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Severance costs</link:label>
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    <link:label id="lab_us-gaap_IncomeTaxReconciliationTaxCreditsResearch_49310a62-dc1c-4cc7-9d4a-c7098347eb86_negatedLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationTaxCreditsResearch" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Research &amp; development tax incentives</link:label>
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    <link:label id="lab_us-gaap_LongTermDebt_a813e7fd-924e-4aef-8f71-9c780b3eebef_totalLabel_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total long-term debt, net</link:label>
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    <link:label id="lab_iclr_IncomeLossFromContinuingOperationsBeforeEquityMethodInvestmentsNoncontrollingInterest_632a6c2d-b38a-4b79-953e-9037ab145384_totalLabel_en-US" xlink:label="lab_iclr_IncomeLossFromContinuingOperationsBeforeEquityMethodInvestmentsNoncontrollingInterest" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income before share of losses from equity method investments</link:label>
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    <link:label id="lab_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_48a295f5-5be4-42c1-84de-fcc0af7b2ab5_terseLabel_en-US" xlink:label="lab_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total accrued interest and penalties</link:label>
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    <link:label id="lab_us-gaap_LeaseholdImprovementsGross_8fab417b-d482-4380-9ac0-30bfe4dd14d6_terseLabel_en-US" xlink:label="lab_us-gaap_LeaseholdImprovementsGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Leasehold improvements</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_b2092773-7d41-47fc-b0f8-7e1ec9574e2c_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Category [Axis]</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Benefit Plan, Plan Assets, Category [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
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    <link:label id="lab_us-gaap_DerivativeLiabilities_cc5d92f3-58b3-4ea5-a742-5cbaf85e4a5c_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative instruments</link:label>
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    <link:label id="lab_iclr_StockRepurchaseProgramAuthorizedPercentage_dc1bf024-915d-48a9-b651-69fe8a0629e9_terseLabel_en-US" xlink:label="lab_iclr_StockRepurchaseProgramAuthorizedPercentage" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Stock repurchase program, authorized percentage (in percent)</link:label>
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    <link:label id="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_a229d05f-01e6-47ae-a3f4-d7753fa489d3_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Issue of restricted share units / performance share units</link:label>
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    <link:label id="lab_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_c8a2ad5d-0ba3-486e-9fa9-f082c369bfcc_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Taxes at Irish statutory rate of 12.5% (2022:12.5%; 2021:12.5%)</link:label>
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    <link:label id="lab_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_271d1043-f2bf-44f1-8455-af7084978710_verboseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other receivables</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assets for Plan Benefits, Defined Benefit Plan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent"/>
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    <link:label id="lab_us-gaap_OtherComprehensiveIncomeLossTaxAbstract_bf7aa833-c507-4e3c-b116-e3aa5f480e73_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossTaxAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income tax expense was allocated to the following components of other comprehensive income:</link:label>
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    <link:label id="lab_us-gaap_EquityMethodInvestments_c4c737dc-ceb9-4f2a-a0b6-b88dd638560a_terseLabel_en-US" xlink:label="lab_us-gaap_EquityMethodInvestments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Equity method investments</link:label>
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    <link:label id="lab_iclr_BiotelResearchLLCMember_e437e027-6c27-4d7d-852c-81ca471b461b_terseLabel_en-US" xlink:label="lab_iclr_BiotelResearchLLCMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Biotel Research LLC</link:label>
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    <link:label id="lab_us-gaap_LongTermLineOfCredit_5fff9cd1-a494-4433-89d8-aed7340d72ac_verboseLabel_en-US" xlink:label="lab_us-gaap_LongTermLineOfCredit" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Non-current bank credit lines and loan facilities (Note 13)</link:label>
    <link:label id="lab_us-gaap_LongTermLineOfCredit_label_en-US" xlink:label="lab_us-gaap_LongTermLineOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-Term Line of Credit, Noncurrent</link:label>
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    <link:label id="lab_iclr_DefinedBenefitPlanPlanAssetsBenefitsPaidAndIncreaseDecreaseForBalanceTransfers_2f24aa99-aa9a-48e7-b865-eb1a0bb33f73_verboseLabel_en-US" xlink:label="lab_iclr_DefinedBenefitPlanPlanAssetsBenefitsPaidAndIncreaseDecreaseForBalanceTransfers" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Benefits paid and transferred balances</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_iclr_DefinedBenefitPlanPlanAssetsBenefitsPaidAndIncreaseDecreaseForBalanceTransfers" xlink:href="iclr-20231231.xsd#iclr_DefinedBenefitPlanPlanAssetsBenefitsPaidAndIncreaseDecreaseForBalanceTransfers"/>
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    <link:label id="lab_iclr_LongTermDebtExcludingCurrentMaturitiesGross_64e79e2b-ea85-4be4-9352-03cbd1942e32_terseLabel_en-US" xlink:label="lab_iclr_LongTermDebtExcludingCurrentMaturitiesGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total long-term debt</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_LongTermDebtExcludingCurrentMaturitiesGross" xlink:to="lab_iclr_LongTermDebtExcludingCurrentMaturitiesGross" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_CommitmentToAcquireLongTermInvestments_74a8c487-0ca6-4e33-993f-a13e305fe3f5_terseLabel_en-US" xlink:label="lab_iclr_CommitmentToAcquireLongTermInvestments" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Commitment to acquire future long-term investments</link:label>
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    <link:label id="lab_iclr_CommitmentToAcquireLongTermInvestments_documentation_en-US" xlink:label="lab_iclr_CommitmentToAcquireLongTermInvestments" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Commitment To Acquire Long-Term Investments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_CommitmentToAcquireLongTermInvestments" xlink:href="iclr-20231231.xsd#iclr_CommitmentToAcquireLongTermInvestments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_CommitmentToAcquireLongTermInvestments" xlink:to="lab_iclr_CommitmentToAcquireLongTermInvestments" xlink:type="arc" order="1"/>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_Range3Member_225e4834-c7ac-4a40-99fa-9341a7a55060_terseLabel_en-US" xlink:label="lab_iclr_Range3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Range 3</link:label>
    <link:label id="lab_iclr_Range3Member_label_en-US" xlink:label="lab_iclr_Range3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Range 3 [Member]</link:label>
    <link:label id="lab_iclr_Range3Member_documentation_en-US" xlink:label="lab_iclr_Range3Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Range 3 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_Range3Member" xlink:href="iclr-20231231.xsd#iclr_Range3Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_Range3Member" xlink:to="lab_iclr_Range3Member" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_VariableRateComponentTwoMember_741e6749-9e7d-49c4-a3e6-c01b652e98c6_terseLabel_en-US" xlink:label="lab_iclr_VariableRateComponentTwoMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Variable rate component two</link:label>
    <link:label id="lab_iclr_VariableRateComponentTwoMember_label_en-US" xlink:label="lab_iclr_VariableRateComponentTwoMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Variable Rate Component Two [Member]</link:label>
    <link:label id="lab_iclr_VariableRateComponentTwoMember_documentation_en-US" xlink:label="lab_iclr_VariableRateComponentTwoMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Variable Rate Component Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_VariableRateComponentTwoMember" xlink:href="iclr-20231231.xsd#iclr_VariableRateComponentTwoMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_VariableRateComponentTwoMember" xlink:to="lab_iclr_VariableRateComponentTwoMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi_ef984d0d-bf5e-4f98-9b78-b31aa654a25f_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Increase (decrease) in equity securities, FV-NI</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Increase (Decrease) in Equity Securities, FV-NI</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi" xlink:to="lab_us-gaap_IncreaseDecreaseInEquitySecuritiesFvNi" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherReceivables_e78e2bda-bfd5-415e-a60a-c0d65915391b_terseLabel_en-US" xlink:label="lab_us-gaap_OtherReceivables" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other receivables</link:label>
    <link:label id="lab_us-gaap_OtherReceivables_label_en-US" xlink:label="lab_us-gaap_OtherReceivables" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Receivables</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivables" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherReceivables"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherReceivables" xlink:to="lab_us-gaap_OtherReceivables" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_Clients25Member_42ea1a65-a028-495d-bcb1-37f6169da387_terseLabel_en-US" xlink:label="lab_iclr_Clients25Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Clients 2-5</link:label>
    <link:label id="lab_iclr_Clients25Member_label_en-US" xlink:label="lab_iclr_Clients25Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Clients 2-5 [Member]</link:label>
    <link:label id="lab_iclr_Clients25Member_documentation_en-US" xlink:label="lab_iclr_Clients25Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Clients 2-5 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_Clients25Member" xlink:href="iclr-20231231.xsd#iclr_Clients25Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_Clients25Member" xlink:to="lab_iclr_Clients25Member" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock_7ccb9502-1827-48c0-ad07-a53ea830ef03_terseLabel_en-US" xlink:label="lab_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Estimated useful lives of assets</link:label>
    <link:label id="lab_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock_label_en-US" xlink:label="lab_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule Of Useful Lives For Property Plant Equipment [Table Text Block]</link:label>
    <link:label id="lab_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock_documentation_en-US" xlink:label="lab_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule Of Useful Lives For Property Plant Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock" xlink:href="iclr-20231231.xsd#iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock" xlink:to="lab_iclr_ScheduleOfUsefulLivesForPropertyPlantEquipmentTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_OtherUndenominatedCapital_ec8a1f75-e68b-4362-aa37-4a67bcfe59c2_terseLabel_en-US" xlink:label="lab_iclr_OtherUndenominatedCapital" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other undenominated capital (Note 18b)</link:label>
    <link:label id="lab_iclr_OtherUndenominatedCapital_label_en-US" xlink:label="lab_iclr_OtherUndenominatedCapital" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Undenominated Capital</link:label>
    <link:label id="lab_iclr_OtherUndenominatedCapital_documentation_en-US" xlink:label="lab_iclr_OtherUndenominatedCapital" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other undenominated capital.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_OtherUndenominatedCapital" xlink:href="iclr-20231231.xsd#iclr_OtherUndenominatedCapital"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_OtherUndenominatedCapital" xlink:to="lab_iclr_OtherUndenominatedCapital" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SeniorSubordinatedNotesMember_97f3439e-ec74-41e8-91d4-670fec173183_terseLabel_en-US" xlink:label="lab_us-gaap_SeniorSubordinatedNotesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Secured Notes</link:label>
    <link:label id="lab_us-gaap_SeniorSubordinatedNotesMember_label_en-US" xlink:label="lab_us-gaap_SeniorSubordinatedNotesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Subordinated Notes [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorSubordinatedNotesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeniorSubordinatedNotesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeniorSubordinatedNotesMember" xlink:to="lab_us-gaap_SeniorSubordinatedNotesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_065c1e65-c396-47d4-8b57-65d3324e75d3_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Participant's contributions percentage of annual compensation (in percent)</link:label>
    <link:label id="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent_label_en-US" xlink:label="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:to="lab_us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_NameOfMajorCustomerDomain_dcdc4563-df76-40e2-887b-1be6e9076580_terseLabel_en-US" xlink:label="lab_srt_NameOfMajorCustomerDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Customer [Domain]</link:label>
    <link:label id="lab_srt_NameOfMajorCustomerDomain_label_en-US" xlink:label="lab_srt_NameOfMajorCustomerDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Customer [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_NameOfMajorCustomerDomain" xlink:to="lab_srt_NameOfMajorCustomerDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent_269ca9aa-f2da-45d8-9483-14d9cfcec195_terseLabel_en-US" xlink:label="lab_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Change in unbilled receivables</link:label>
    <link:label id="lab_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent_label_en-US" xlink:label="lab_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Increase (Decrease) In Contract with Customer, Asset, Gross, Current</link:label>
    <link:label id="lab_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent_documentation_en-US" xlink:label="lab_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Increase (Decrease) In Contract with Customer, Asset, Gross, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent" xlink:href="iclr-20231231.xsd#iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent" xlink:to="lab_iclr_IncreaseDecreaseInContractwithCustomerAssetGrossCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationOtherReconcilingItems_6857c0d5-13fd-49fe-9496-85d4bf1851d8_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other</link:label>
    <link:label id="lab_us-gaap_IncomeTaxReconciliationOtherReconcilingItems_label_en-US" xlink:label="lab_us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeTaxReconciliationOtherReconcilingItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:to="lab_us-gaap_IncomeTaxReconciliationOtherReconcilingItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_761eaa59-e76e-44e0-b82f-20aca5c3e8af_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Options Granted Under Plans</link:label>
    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_label_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember_95cf7a0c-2678-4c29-8084-1b2406d6f4c6_terseLabel_en-US" xlink:label="lab_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">ICON Development Solutions Limited pension plan</link:label>
    <link:label id="lab_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember_label_en-US" xlink:label="lab_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">ICON Development Solutions Limited Pension Plan [Member]</link:label>
    <link:label id="lab_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember_documentation_en-US" xlink:label="lab_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">ICON Development Solutions Limited Pension Plan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember" xlink:href="iclr-20231231.xsd#iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember" xlink:to="lab_iclr_ICONDevelopmentSolutionsLimitedPensionPlanMember" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_RestOfEuropeAndOtherCountriesMember_9c244a72-3172-4699-949f-dfe9243197fb_terseLabel_en-US" xlink:label="lab_iclr_RestOfEuropeAndOtherCountriesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other</link:label>
    <link:label id="lab_iclr_RestOfEuropeAndOtherCountriesMember_label_en-US" xlink:label="lab_iclr_RestOfEuropeAndOtherCountriesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Rest Of Europe And Other Countries [Member]</link:label>
    <link:label id="lab_iclr_RestOfEuropeAndOtherCountriesMember_documentation_en-US" xlink:label="lab_iclr_RestOfEuropeAndOtherCountriesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Rest Of Europe And Other Countries [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_RestOfEuropeAndOtherCountriesMember" xlink:href="iclr-20231231.xsd#iclr_RestOfEuropeAndOtherCountriesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_RestOfEuropeAndOtherCountriesMember" xlink:to="lab_iclr_RestOfEuropeAndOtherCountriesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OperatingLeaseLiability_f80b7aa3-6ba8-44ec-bb6a-7784b1703d2c_verboseLabel_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total</link:label>
    <link:label id="lab_us-gaap_OperatingLeaseLiability_label_en-US" xlink:label="lab_us-gaap_OperatingLeaseLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating Lease, Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OperatingLeaseLiability" xlink:to="lab_us-gaap_OperatingLeaseLiability" xlink:type="arc" order="1"/>
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    <link:label id="lab_us-gaap_DefinedContributionPlanCostRecognized_f63ff9f8-82e7-4a83-89b3-7249aa9cfded_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedContributionPlanCostRecognized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Defined contribution plan, cost</link:label>
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    <link:label id="lab_us-gaap_NontradeReceivablesCurrent_fc37f749-88e4-4433-b5d9-409f89c1deed_terseLabel_en-US" xlink:label="lab_us-gaap_NontradeReceivablesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other receivables</link:label>
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    <link:label id="lab_us-gaap_IncomeTaxEffectsAllocatedDirectlyToEquity_878a262f-41f1-4f14-82b5-57ed8c02fd22_totalLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxEffectsAllocatedDirectlyToEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total</link:label>
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    <link:label id="lab_us-gaap_PlanNameAxis_e6d0b9a1-ca02-4ea1-b527-8ab4b3867ea1_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Plan Name [Axis]</link:label>
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    <link:label id="lab_us-gaap_DebtDisclosureAbstract_dc602cff-decd-42d4-8256-165b3f618cd6_terseLabel_en-US" xlink:label="lab_us-gaap_DebtDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Disclosure [Abstract]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DebtDisclosureAbstract" xlink:to="lab_us-gaap_DebtDisclosureAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_d2e29190-d9c0-4850-84ac-2c85b793f406_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income tax benefit related to stock compensation</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
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    <link:label id="lab_us-gaap_EarningsPerShareAbstract_b32742c4-2fff-4e58-ae34-4fa1e78a9f16_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net income per ordinary share (Note 24):</link:label>
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    <link:label id="lab_us-gaap_CommonStockValue_62257010-4632-4b31-86a4-4f3eb13a2cb0_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Ordinary shares par value 6 euro cents per share; 100,000,000 shares authorized, (Note 18). 82,495,086 shares issued and outstanding at December 31, 2023 and 81,723,555 shares issued and outstanding at December 31, 2022.</link:label>
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    <link:label id="lab_us-gaap_TradeNamesMember_f3b345df-c10e-4044-9cec-73cb219e7505_terseLabel_en-US" xlink:label="lab_us-gaap_TradeNamesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Trade names &amp; brands</link:label>
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    <link:label id="lab_us-gaap_BaseRateMember_6ef3a58a-9ad4-45fe-a1e0-2a4ba12ca999_terseLabel_en-US" xlink:label="lab_us-gaap_BaseRateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Base rate</link:label>
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    <link:label id="lab_us-gaap_BuildingMember_73cb6dfd-24f6-4011-85cc-cd571b491b0b_terseLabel_en-US" xlink:label="lab_us-gaap_BuildingMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Buildings &#160;</link:label>
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    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife_8a01cc9d-6d8f-470b-b07d-f368c9d3613c_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Amortization period</link:label>
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    <link:label id="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_1a9c2cdc-223c-4cf3-9e30-225eb570e8e6_terseLabel_en-US" xlink:label="lab_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2027</link:label>
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    <link:label id="lab_us-gaap_RevenueFromExternalCustomersByGeographicAreasTableTextBlock_5d138ec5-1719-4d59-9023-643663d278ee_terseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromExternalCustomersByGeographicAreasTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Distribution of Net Revenue by Geographical Area</link:label>
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    <link:label id="lab_us-gaap_ForeignCountryMember_4ea97c8b-4cfe-4398-b175-6116e1830af5_terseLabel_en-US" xlink:label="lab_us-gaap_ForeignCountryMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Foreign Country</link:label>
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    <link:label id="lab_us-gaap_AccruedIncomeTaxesNoncurrent_910c94e8-56fb-4832-8a24-d1da571bd6c6_terseLabel_en-US" xlink:label="lab_us-gaap_AccruedIncomeTaxesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Non-current income taxes payable</link:label>
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    <link:label id="lab_us-gaap_EarningsPerShareTextBlock_9d9958cc-0d9f-485c-a7f5-3e1c47f9bbc6_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net Income Per Ordinary Share</link:label>
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    <link:label id="lab_us-gaap_ShareRepurchaseProgramDomain_352fa628-c26d-43f9-9ee2-e958f4e3e3e7_terseLabel_en-US" xlink:label="lab_us-gaap_ShareRepurchaseProgramDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share Repurchase Program [Domain]</link:label>
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    <link:label id="lab_iclr_LongTermDebtMaturityYearFiveAndThereafter_08413e3d-697f-451a-be2e-153ad3e934b5_terseLabel_en-US" xlink:label="lab_iclr_LongTermDebtMaturityYearFiveAndThereafter" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2028 and thereafter</link:label>
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    <link:label id="lab_dei_EntityAddressCityOrTown_66190f41-17bc-45fa-a359-09362fa26f30_terseLabel_en-US" xlink:label="lab_dei_EntityAddressCityOrTown" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Address, City or Town</link:label>
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    <link:label id="lab_us-gaap_RestructuringCharges_fad3d7a1-35bb-4ed0-8aac-9ce21c7ab8c4_terseLabel_en-US" xlink:label="lab_us-gaap_RestructuringCharges" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Additional provision in the year</link:label>
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    <link:label id="lab_us-gaap_BusinessCombinationsAbstract_79b06296-6f6e-4113-87d3-32a811a05a90_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combinations [Abstract]</link:label>
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    <link:label id="lab_us-gaap_FurnitureAndFixturesGross_d72c2f3b-ace0-4834-968f-266054b4b046_terseLabel_en-US" xlink:label="lab_us-gaap_FurnitureAndFixturesGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Office furniture and fixtures</link:label>
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    <link:label id="lab_us-gaap_CommonStockSharesAuthorized_c48760ab-7ef1-4e48-b7ad-3343cf44ce9c_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Ordinary shares, shares authorized (in shares)</link:label>
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    <link:label id="lab_iclr_IncomeTaxBenefitMember_51548301-de1d-484d-a671-506b958789cf_terseLabel_en-US" xlink:label="lab_iclr_IncomeTaxBenefitMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Provision for income taxes</link:label>
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    <link:label id="lab_dei_DocumentInformationTable_7f8712a4-c00a-456d-b13e-6dada0b1a958_terseLabel_en-US" xlink:label="lab_dei_DocumentInformationTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Information [Table]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityRegistrantName" xlink:to="lab_dei_EntityRegistrantName" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock_b15e8393-fe0a-4631-b12f-03de943bf5cb_terseLabel_en-US" xlink:label="lab_iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Summary of RSU and PSU Activity</link:label>
    <link:label id="lab_iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock_label_en-US" xlink:label="lab_iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule Of Share Based Compensation Restricted Stock Units Performance Stock Units Award Activity [Table Text Block]</link:label>
    <link:label id="lab_iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock_documentation_en-US" xlink:label="lab_iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule Of Share Based Compensation Restricted Stock Units Performance Stock Units Award Activity [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock" xlink:href="iclr-20231231.xsd#iclr_ScheduleOfShareBasedCompensationRestrictedStockUnitsPerformanceStockUnitsAwardActivityTableTextBlock"/>
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    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_83757ddf-b641-493b-b1ba-c7b9d2892e80_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">2025</link:label>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Finite-Lived Intangible Asset, Expected Amortization, Year Two</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_43b53146-7c7d-43f1-a173-04f67bc67fbc_terseLabel_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other net assets</link:label>
    <link:label id="lab_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_label_en-US" xlink:label="lab_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Increase (Decrease) in Other Current Liabilities</link:label>
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    <link:label id="lab_us-gaap_CostOfSalesMember_bed78e4d-edc1-4646-a72f-5131455cc9ea_verboseLabel_en-US" xlink:label="lab_us-gaap_CostOfSalesMember" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cost of Sales</link:label>
    <link:label id="lab_us-gaap_CostOfSalesMember_afa0aaad-68b1-44b4-bfb6-953345f54951_terseLabel_en-US" xlink:label="lab_us-gaap_CostOfSalesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Direct costs</link:label>
    <link:label id="lab_us-gaap_CostOfSalesMember_label_en-US" xlink:label="lab_us-gaap_CostOfSalesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cost of Sales [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostOfSalesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostOfSalesMember" xlink:to="lab_us-gaap_CostOfSalesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EmployeeSeveranceMember_90b4c31a-9f23-4fcb-8b9c-cb6e1ce07230_terseLabel_en-US" xlink:label="lab_us-gaap_EmployeeSeveranceMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Workforce reductions</link:label>
    <link:label id="lab_us-gaap_EmployeeSeveranceMember_label_en-US" xlink:label="lab_us-gaap_EmployeeSeveranceMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Employee Severance [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeSeveranceMember" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EmployeeSeveranceMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EmployeeSeveranceMember" xlink:to="lab_us-gaap_EmployeeSeveranceMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract_a7d83949-0973-405c-a82e-838e3fa38eb2_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]</link:label>
    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract" xlink:to="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_AuditorName_db036a35-0126-4549-9cca-22caca58bf73_terseLabel_en-US" xlink:label="lab_dei_AuditorName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Auditor name</link:label>
    <link:label id="lab_dei_AuditorName_label_en-US" xlink:label="lab_dei_AuditorName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Auditor Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AuditorName" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AuditorName"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AuditorName" xlink:to="lab_dei_AuditorName" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromLinesOfCredit_52943755-88cb-4cbe-afeb-e4a4418fd615_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Drawdown of credit lines and facilities</link:label>
    <link:label id="lab_us-gaap_ProceedsFromLinesOfCredit_label_en-US" xlink:label="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Proceeds from Lines of Credit</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ProceedsFromLinesOfCredit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromLinesOfCredit" xlink:to="lab_us-gaap_ProceedsFromLinesOfCredit" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_706d3387-c9e6-480c-b7ec-5b8258a5ff39_negatedLabel_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Less accumulated depreciation and asset write offs</link:label>
    <link:label id="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_label_en-US" xlink:label="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="lab_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ContractWithCustomerAssetCreditLossExpense_08fd3f15-11c8-40d5-85c8-db186889068d_terseLabel_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetCreditLossExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Bad debt expense</link:label>
    <link:label id="lab_us-gaap_ContractWithCustomerAssetCreditLossExpense_label_en-US" xlink:label="lab_us-gaap_ContractWithCustomerAssetCreditLossExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Contract with Customer, Asset, Credit Loss Expense (Reversal)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractWithCustomerAssetCreditLossExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense" xlink:to="lab_us-gaap_ContractWithCustomerAssetCreditLossExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_iclr_TopClientMember_6d36db49-e800-4552-a196-8b606d095bf9_terseLabel_en-US" xlink:label="lab_iclr_TopClientMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Top client</link:label>
    <link:label id="lab_iclr_TopClientMember_label_en-US" xlink:label="lab_iclr_TopClientMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Top Client [Member]</link:label>
    <link:label id="lab_iclr_TopClientMember_documentation_en-US" xlink:label="lab_iclr_TopClientMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Top Client [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_iclr_TopClientMember" xlink:href="iclr-20231231.xsd#iclr_TopClientMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_iclr_TopClientMember" xlink:to="lab_iclr_TopClientMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityCentralIndexKey_268412c4-e6ea-4088-a27d-5446102306ff_terseLabel_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Central Index Key</link:label>
    <link:label id="lab_dei_EntityCentralIndexKey_label_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Central Index Key</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCentralIndexKey" xlink:to="lab_dei_EntityCentralIndexKey" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount_7a8e2e97-8307-4d63-802b-ef102ca6795b_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Acquisition-related gain</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount_a8f0787b-b715-4684-8b53-1a1f3b1444f1_terseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Acquisition related costs</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Bargain Purchase, Gain Recognized, Amount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount" xlink:to="lab_us-gaap_BusinessCombinationBargainPurchaseGainRecognizedAmount" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsGross_f7c23109-7127-4015-b433-cb468cc0e2eb_terseLabel_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total cost</link:label>
    <link:label id="lab_us-gaap_FiniteLivedIntangibleAssetsGross_label_en-US" xlink:label="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Finite-Lived Intangible Assets, Gross</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="lab_us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_5fe67cf3-8034-4575-a37c-129f1cbcff19_verboseLabel_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts receivable and unbilled revenue</link:label>
    <link:label id="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_label_en-US" xlink:label="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:to="lab_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_IncomeTaxAuthorityDomain_e24da912-9a1a-41b7-b91a-74d06974c0f5_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Tax Authority [Domain]</link:label>
    <link:label id="lab_us-gaap_IncomeTaxAuthorityDomain_label_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Tax Authority [Domain]</link:label>
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    <link:label id="lab_us-gaap_IncomeTaxAuthorityNameAxis_ef6c436f-f72e-4cc4-8d4c-62459db14a2e_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxAuthorityNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Tax Authority, Name [Axis]</link:label>
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    <link:label id="lab_us-gaap_CapitalizedComputerSoftwareGross_1007352e-7317-44fd-92a5-c917f0265f8c_terseLabel_en-US" xlink:label="lab_us-gaap_CapitalizedComputerSoftwareGross" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Computer equipment and software</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized_1a6e77f4-0350-4a2d-9b06-f5710cc42ce9_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Additional number of ordinary shares which have been reserved for issuance (in shares)</link:label>
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    <link:label id="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_3be5f4cd-b15d-4133-8b7a-61a4930cedc2_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Purchase of property, plant and equipment</link:label>
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    <link:label id="lab_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_73bca6e9-ee9f-498d-a84a-3f353b896fcb_terseLabel_en-US" xlink:label="lab_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Weighted Average Remaining Contractual Life</link:label>
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    <link:label id="lab_us-gaap_Assets_81f6d8e9-69bb-47ef-a0fd-85a3e0ab29ea_totalLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total Assets</link:label>
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    <link:label id="lab_us-gaap_EquipmentMember_61d6f2c8-0969-45d2-81dd-13d838cf0297_terseLabel_en-US" xlink:label="lab_us-gaap_EquipmentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Laboratory equipment &#160;</link:label>
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    <link:label id="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_68cd6741-7ebf-4b3d-9708-073301e3f71a_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cash flows from financing activities:</link:label>
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