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    <link:label id="lab_omc_ForfeitedNonVestedAccountBalances_documentation_en-US" xlink:label="lab_omc_ForfeitedNonVestedAccountBalances" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Forfeited non-vested account balances</link:label>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Description of Plan [Table]</link:label>
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    <link:label id="lab_us-gaap_MutualFundMember_019e9362-fbb2-7954-887a-6127048103cc_terseLabel_en-US" xlink:label="lab_us-gaap_MutualFundMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Mutual Funds</link:label>
    <link:label id="lab_us-gaap_MutualFundMember_label_en-US" xlink:label="lab_us-gaap_MutualFundMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Mutual Fund [Member]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MutualFundMember" xlink:to="lab_us-gaap_MutualFundMember" xlink:type="arc" order="1"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrected_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrected" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution, Corrected</link:label>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Related Party and Party-in-Interest Transactions [Table]</link:label>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease_019efa51-94ad-73f4-8f13-17aab4fa1213_totalLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecrease" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Deductions</link:label>
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    <link:label id="lab_omc_SettlementProceedsAbstract_documentation_en-US" xlink:label="lab_omc_SettlementProceedsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Settlement Proceeds [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_SettlementProceedsAbstract" xlink:href="omc-20251231.xsd#omc_SettlementProceedsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_SettlementProceedsAbstract" xlink:to="lab_omc_SettlementProceedsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueInputsLevel1Member_019f145a-3892-7b86-b340-c49016e1fa9b_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 1</link:label>
    <link:label id="lab_us-gaap_FairValueInputsLevel1Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel1Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 1 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel1Member" xlink:to="lab_us-gaap_FairValueInputsLevel1Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock_019efa5d-39a2-7d8b-8d39-240d1ca40645_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment in Fully Benefit Responsive Contracts</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Fully Benefit-Responsive Investment Contract [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Investment, Fair Value and NAV [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MeasurementInputTypeAxis_019e9395-5073-7669-ae70-fa173ddaceea_terseLabel_en-US" xlink:label="lab_us-gaap_MeasurementInputTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Axis]</link:label>
    <link:label id="lab_us-gaap_MeasurementInputTypeAxis_label_en-US" xlink:label="lab_us-gaap_MeasurementInputTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MeasurementInputTypeAxis" xlink:to="lab_us-gaap_MeasurementInputTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAsset_019e9378-e04a-752d-bf78-47b36c1e2439_totalLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAsset" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Assets</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAsset_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Asset</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAsset"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAsset" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAsset" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_019e9379-fc86-7731-975d-8145ddf4f0bb_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Assets:</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Asset [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAssetAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_RangeAxis_019e9395-5073-725f-b1c5-2a28c5480290_terseLabel_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Axis]</link:label>
    <link:label id="lab_srt_RangeAxis_label_en-US" xlink:label="lab_srt_RangeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Statistical Measurement [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_RangeAxis" xlink:to="lab_srt_RangeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_019efa4f-323e-7783-bf26-252d58829ada_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Additions:</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable_019e938e-6cfc-7440-a50f-e6149575a8cb_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Statement of Change in Net Asset Available for Benefit [Table]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Statement of Change in Net Asset Available for Benefit [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock_019f1442-93f0-7705-8f66-e802147facf5_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Payment to Participant</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Payment to Participant [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanPaymentToParticipantPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan_019efa52-cf4e-720c-87b2-f27275c00106_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Assets transferred into Plan</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Transfer to (from) Plan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitTransferToFromExternalPlan" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanLiability_019e937e-409b-7e8b-9416-d54feedb891a_totalLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanLiability" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Liabilities</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanLiability_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanLiability" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Liability</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanLiability" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanLiability"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanLiability" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanLiability" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_DueToBrokerForInvestmentsPurchased_019e937d-acdb-76f3-9aca-62fca1cf1abd_terseLabel_en-US" xlink:label="lab_omc_DueToBrokerForInvestmentsPurchased" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Due to broker for investments purchased</link:label>
    <link:label id="lab_omc_DueToBrokerForInvestmentsPurchased_label_en-US" xlink:label="lab_omc_DueToBrokerForInvestmentsPurchased" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Due to broker for investments purchased</link:label>
    <link:label id="lab_omc_DueToBrokerForInvestmentsPurchased_documentation_en-US" xlink:label="lab_omc_DueToBrokerForInvestmentsPurchased" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Due to broker for investments purchased</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_DueToBrokerForInvestmentsPurchased" xlink:href="omc-20251231.xsd#omc_DueToBrokerForInvestmentsPurchased"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_DueToBrokerForInvestmentsPurchased" xlink:to="lab_omc_DueToBrokerForInvestmentsPurchased" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_AmendmentFlag_019f1499-7983-7bb1-9e6d-0cce3132c1a3_terseLabel_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Amendment Flag</link:label>
    <link:label id="lab_dei_AmendmentFlag_label_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Amendment Flag</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_AmendmentFlag" xlink:to="lab_dei_AmendmentFlag" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock_019f143f-16aa-7122-a660-235678939a57_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Basis of Accounting</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Basis of Accounting [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanBasisOfAccountingPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_019f13ae-f76a-7d10-94d0-f5c8e455aa59_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Asset Held for Investment [Table]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Asset Held for Investment [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ValuationTechniqueDomain_019e9395-5073-7f2c-a6a9-5f76b8c6f12d_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationTechniqueDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Valuation Approach and Technique [Domain]</link:label>
    <link:label id="lab_us-gaap_ValuationTechniqueDomain_label_en-US" xlink:label="lab_us-gaap_ValuationTechniqueDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Valuation Approach and Technique [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationTechniqueDomain" xlink:to="lab_us-gaap_ValuationTechniqueDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares_019f13b4-e8b0-7e1c-b4cd-f97336979eef_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Shares</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Investment, Number of Shares</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentNumberOfShares" xlink:type="arc" order="1"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanAbstract" xlink:type="arc" order="1"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavTableTextBlock"/>
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    <link:label id="lab_srt_ScenarioUnspecifiedDomain_019efb23-ab5c-710b-9a2f-7a351d4a5b08_terseLabel_en-US" xlink:label="lab_srt_ScenarioUnspecifiedDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Scenario [Domain]</link:label>
    <link:label id="lab_srt_ScenarioUnspecifiedDomain_label_en-US" xlink:label="lab_srt_ScenarioUnspecifiedDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Scenario [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_ScenarioUnspecifiedDomain" xlink:to="lab_srt_ScenarioUnspecifiedDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InvestmentTypeCategorizationMember_019e935c-0a17-7c3d-81eb-94aaeca9c872_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentTypeCategorizationMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments [Domain]</link:label>
    <link:label id="lab_us-gaap_InvestmentTypeCategorizationMember_label_en-US" xlink:label="lab_us-gaap_InvestmentTypeCategorizationMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investments [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember" xlink:to="lab_us-gaap_InvestmentTypeCategorizationMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock_019f143f-d54a-7d7c-8b18-8f914aa55714_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Use of Estimate</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Use of Estimate [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanUseOfEstimatePolicyTextBlock"/>
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    <link:label id="lab_omc_AccruedInterestAndDividends_019e9375-0391-7abe-81f8-8b3ad99a56bb_terseLabel_en-US" xlink:label="lab_omc_AccruedInterestAndDividends" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Accrued interest and dividends</link:label>
    <link:label id="lab_omc_AccruedInterestAndDividends_label_en-US" xlink:label="lab_omc_AccruedInterestAndDividends" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Accrued interest and dividends</link:label>
    <link:label id="lab_omc_AccruedInterestAndDividends_documentation_en-US" xlink:label="lab_omc_AccruedInterestAndDividends" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Accrued interest and dividends</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_AccruedInterestAndDividends" xlink:href="omc-20251231.xsd#omc_AccruedInterestAndDividends"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_AccruedInterestAndDividends" xlink:to="lab_omc_AccruedInterestAndDividends" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain_019e935c-0a18-7369-8078-b610c18b4219_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Related Party and Party-in-Interest [Domain]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Related Party and Party-in-Interest [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_CoverAbstract_label_en-US" xlink:label="lab_dei_CoverAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Cover [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CoverAbstract"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionLineItems_019efb1d-93e9-7da2-b119-f4266b53511b_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionLineItems"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis_019e935c-0a18-78c4-8a13-5c1716ea6710_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Related Party and Party-in-Interest [Axis]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Related Party and Party-in-Interest [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock_019f1447-3f57-7734-bf98-ba7a6f42b75e_terseLabel_en-US" xlink:label="lab_omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments Measured at Fair Value on a Recurring Basis [Table Text Block]</link:label>
    <link:label id="lab_omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock_label_en-US" xlink:label="lab_omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investments Measured at Fair Value on a Recurring Basis [Table Text Block]</link:label>
    <link:label id="lab_omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock_documentation_en-US" xlink:label="lab_omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Investments Measured at Fair Value on a Recurring Basis</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock" xlink:href="omc-20251231.xsd#omc_InvestmentsMeasuredAtFairValueOnARecurringBasisTableTextBlock"/>
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    <link:label id="lab_us-gaap_InvestmentTypeAxis_019e935c-0a17-779c-ae1f-42c969eba326_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment Type [Axis]</link:label>
    <link:label id="lab_us-gaap_InvestmentTypeAxis_label_en-US" xlink:label="lab_us-gaap_InvestmentTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestmentTypeAxis" xlink:to="lab_us-gaap_InvestmentTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution_019efa46-01e9-7454-8bd5-0421ecce6d58_totalLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Contributions:</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase from Contribution</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForContribution" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover_019e9390-750c-73e2-a53a-fb26aaf62c09_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Participants</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForParticipantContributionExcludingRollover"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_019efad3-d83d-765c-8af8-2735829250c4_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investments, net appreciation (depreciation) in the fair value</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecreaseForGainLossOnInvestment" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment_019efa43-e84b-7440-b284-13ced49e98ce_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Dividend and interest income</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForInterestAndDividendIncomeOnInvestment"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_019efa61-691c-71c4-8cb6-5ad0aaaf80eb_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Description of Plan [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Description of Plan [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_EBP004Member_019e935e-0dc2-717f-9c38-65bf099ceba3_terseLabel_en-US" xlink:label="lab_omc_EBP004Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP 004 [Member]</link:label>
    <link:label id="lab_omc_EBP004Member_label_en-US" xlink:label="lab_omc_EBP004Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP 004 [Member]</link:label>
    <link:label id="lab_omc_EBP004Member_documentation_en-US" xlink:label="lab_omc_EBP004Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">EBP 004</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_EBP004Member" xlink:href="omc-20251231.xsd#omc_EBP004Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_EBP004Member" xlink:to="lab_omc_EBP004Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_019f13b1-36c5-7676-9768-ed6d7d898b11_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanPlanNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Plan Number</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanPlanNumber_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanPlanNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Plan Number</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanPlanNumber"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanPlanNumber" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanPlanNumber" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_019e9395-5073-7f36-8f41-0a7824c138cb_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Investment, Fair Value and NAV [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Investment, Fair Value and NAV [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentFairValueAndNavLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock_019efa58-3156-7e6a-b242-f31dd13bba5a_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Description of Plan</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Description of Plan [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp_019f148c-6925-7226-b229-31b2e1282f06_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution, Pending Correction in VFCP</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution, Pending Correction in VFCP</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionPendingCorrectionInVfcp" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems_019e938e-6cfc-785d-aa44-17b376725885_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Statement of Change in Net Asset Available for Benefit [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Statement of Change in Net Asset Available for Benefit [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable_019e935c-0a17-715e-9437-070f074a6d32_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Statement of Net Asset Available for Benefit [Table]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Statement of Net Asset Available for Benefit [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_019f13ae-f76a-7eb9-b82c-35237adbad59_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Asset Held for Investment [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Asset Held for Investment [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_019e9369-cbe4-738d-8bfd-de75b7d19b13_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Company Stock</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Employer, Common Stock [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerCommonStockMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Asset Held for Investment [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfAssetHeldForInvestmentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_019efa63-7c80-7e82-bab0-f3519bdbe633_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Accounting Policy [Table]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Accounting Policy [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease_019efa4e-4324-7624-abe3-fe2fa9700a06_totalLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Additions</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncrease" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InvestmentIdentifierAxis_019f13ae-f76a-7526-8d7f-48acfc677daf_terseLabel_en-US" xlink:label="lab_us-gaap_InvestmentIdentifierAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Investment, Identifier [Axis]</link:label>
    <link:label id="lab_us-gaap_InvestmentIdentifierAxis_label_en-US" xlink:label="lab_us-gaap_InvestmentIdentifierAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Investment, Identifier [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIdentifierAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIdentifierAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InvestmentIdentifierAxis" xlink:to="lab_us-gaap_InvestmentIdentifierAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense_019efa50-f518-7f96-b24a-3a02334a4744_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Administrative expenses</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForAdministrativeExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment_019f143d-2ca7-775f-9e80-2832c5897d06_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Asset Held for Investment</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Asset Held for Investment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestment" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock_019f1445-6076-7db5-8d12-be717fb9cec7_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Risk and Uncertainty</link:label>
    <link:label id="lab_us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Risk and Uncertainty [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock" xlink:to="lab_us-gaap-ebp_EbpRiskAndUncertaintyPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentInformationLineItems_019e9383-f5d6-7410-b5c5-44efc50c57e2_terseLabel_en-US" xlink:label="lab_dei_DocumentInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Document Information [Line Items]</link:label>
    <link:label id="lab_dei_DocumentInformationLineItems_label_en-US" xlink:label="lab_dei_DocumentInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Information [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentInformationLineItems" xlink:to="lab_dei_DocumentInformationLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_FairValueAbstract_label_en-US" xlink:label="lab_omc_FairValueAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value [Abstract]</link:label>
    <link:label id="lab_omc_FairValueAbstract_documentation_en-US" xlink:label="lab_omc_FairValueAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_FairValueAbstract" xlink:href="omc-20251231.xsd#omc_FairValueAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_FairValueAbstract" xlink:to="lab_omc_FairValueAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_DelinquentParticipantContributionsTextBlock_019f1477-339e-7d02-9adc-912320568c61_terseLabel_en-US" xlink:label="lab_omc_DelinquentParticipantContributionsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Delinquent Participant Contributions</link:label>
    <link:label id="lab_omc_DelinquentParticipantContributionsTextBlock_label_en-US" xlink:label="lab_omc_DelinquentParticipantContributionsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Delinquent Participant Contributions [Text Block]</link:label>
    <link:label id="lab_omc_DelinquentParticipantContributionsTextBlock_documentation_en-US" xlink:label="lab_omc_DelinquentParticipantContributionsTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Delinquent Participant Contributions</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_DelinquentParticipantContributionsTextBlock" xlink:href="omc-20251231.xsd#omc_DelinquentParticipantContributionsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_DelinquentParticipantContributionsTextBlock" xlink:to="lab_omc_DelinquentParticipantContributionsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_StatementScenarioAxis_019efb23-ab5c-7f59-b31b-02d2bcad4ea7_terseLabel_en-US" xlink:label="lab_srt_StatementScenarioAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Scenario [Axis]</link:label>
    <link:label id="lab_srt_StatementScenarioAxis_label_en-US" xlink:label="lab_srt_StatementScenarioAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Scenario [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementScenarioAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_StatementScenarioAxis" xlink:to="lab_srt_StatementScenarioAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_DueFromBrokerForInvestmentsSold_019e9376-0810-7a38-9a20-edac24cd43ee_terseLabel_en-US" xlink:label="lab_omc_DueFromBrokerForInvestmentsSold" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Due from broker for investments sold</link:label>
    <link:label id="lab_omc_DueFromBrokerForInvestmentsSold_label_en-US" xlink:label="lab_omc_DueFromBrokerForInvestmentsSold" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Due from broker for investments sold</link:label>
    <link:label id="lab_omc_DueFromBrokerForInvestmentsSold_documentation_en-US" xlink:label="lab_omc_DueFromBrokerForInvestmentsSold" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Due from broker for investments sold</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_DueFromBrokerForInvestmentsSold" xlink:href="omc-20251231.xsd#omc_DueFromBrokerForInvestmentsSold"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_DueFromBrokerForInvestmentsSold" xlink:to="lab_omc_DueFromBrokerForInvestmentsSold" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Statement of Change in Net Asset Available for Benefit [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfChangeInNetAssetAvailableForBenefitAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueInputsLevel2Member_019f145a-6e0e-7f40-9c4a-f3a4640909b3_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 2</link:label>
    <link:label id="lab_us-gaap_FairValueInputsLevel2Member_label_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value, Inputs, Level 2 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel2Member" xlink:to="lab_us-gaap_FairValueInputsLevel2Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MeasurementInputTypeDomain_019e9395-5073-7e39-8d2e-0ab65ef45fcf_terseLabel_en-US" xlink:label="lab_us-gaap_MeasurementInputTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Domain]</link:label>
    <link:label id="lab_us-gaap_MeasurementInputTypeDomain_label_en-US" xlink:label="lab_us-gaap_MeasurementInputTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Measurement Input Type [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MeasurementInputTypeDomain" xlink:to="lab_us-gaap_MeasurementInputTypeDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_019efa64-c4b9-71fb-b06f-1ff5c53db4a8_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Fully Benefit-Responsive Investment Contract [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Fully Benefit-Responsive Investment Contract [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanFullyBenefitResponsiveInvestmentContractLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution_019e938e-6cfc-7945-ae57-d4f636fdb84c_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Employer</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseForEmployerContribution" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp_019f148a-5d1d-7ffd-aac9-da56b53ef1c0_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution, Corrected Outside VFCP</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution, Corrected Outside VFCP</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionCorrectedOutsideVfcp" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SubsequentEventTypeAxis_019efb23-ab5c-794b-8147-73a44063f5fb_terseLabel_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Axis]</link:label>
    <link:label id="lab_us-gaap_SubsequentEventTypeAxis_label_en-US" xlink:label="lab_us-gaap_SubsequentEventTypeAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Subsequent Event Type [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SubsequentEventTypeAxis" xlink:to="lab_us-gaap_SubsequentEventTypeAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain_019e935c-0a17-7b27-bf14-6cd26d3409bf_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Allocation Status [Domain]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Allocation Status [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_ScheduleOfDelinquentContributionsAbstract_label_en-US" xlink:label="lab_omc_ScheduleOfDelinquentContributionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Schedule of Delinquent Contributions [Abstract]</link:label>
    <link:label id="lab_omc_ScheduleOfDelinquentContributionsAbstract_documentation_en-US" xlink:label="lab_omc_ScheduleOfDelinquentContributionsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Schedule of Delinquent Contributions [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_ScheduleOfDelinquentContributionsAbstract" xlink:href="omc-20251231.xsd#omc_ScheduleOfDelinquentContributionsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_ScheduleOfDelinquentContributionsAbstract" xlink:to="lab_omc_ScheduleOfDelinquentContributionsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable_019efb1c-5cb3-7c85-a5b4-beaac9a2641b_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Tax Status [Table]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Tax Status [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_019efa52-2825-7c42-930c-b5c342b598ad_totalLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Net increase</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase (Decrease)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitIncreaseDecrease" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock_019efb16-350a-7683-9b74-df7b1341cc93_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Party-In-Interest Transactions</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Related Party and Party-in-Interest Transactions [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanRelatedPartyAndPartyInInterestTransactionsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanReceivable_019e9377-eda6-733c-95c2-45b9f483fdd6_totalLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanReceivable" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xml:lang="en-US">Total Receivables</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanReceivable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Receivable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanReceivable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanReceivable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanReceivable" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_PlanAmendmentOrTerminationAbstract_label_en-US" xlink:label="lab_omc_PlanAmendmentOrTerminationAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Plan Amendment or Termination [Abstract]</link:label>
    <link:label id="lab_omc_PlanAmendmentOrTerminationAbstract_documentation_en-US" xlink:label="lab_omc_PlanAmendmentOrTerminationAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Plan Amendment or Termination [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_PlanAmendmentOrTerminationAbstract" xlink:href="omc-20251231.xsd#omc_PlanAmendmentOrTerminationAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_PlanAmendmentOrTerminationAbstract" xlink:to="lab_omc_PlanAmendmentOrTerminationAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable_019e9371-2233-7ece-b88d-323ea2c7da08_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Employer contributions</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Employer Contribution, Receivable</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanEmployerContributionReceivable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_019efa50-a90e-7f67-8feb-ed712e224cf0_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Benefits paid</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseForPaymentToParticipant" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan_019f1474-fc1f-75c7-8e21-1d39882d1655_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Delinquent Participant Contributions</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan_019f150c-d626-7495-a4f8-2aaa6186ccf6_verboseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTransferredLateToPlan" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_DelinquentParticipantContributionsAbstract_label_en-US" xlink:label="lab_omc_DelinquentParticipantContributionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Delinquent Participant Contributions [Abstract]</link:label>
    <link:label id="lab_omc_DelinquentParticipantContributionsAbstract_documentation_en-US" xlink:label="lab_omc_DelinquentParticipantContributionsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Delinquent Participant Contributions [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_DelinquentParticipantContributionsAbstract" xlink:href="omc-20251231.xsd#omc_DelinquentParticipantContributionsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_DelinquentParticipantContributionsAbstract" xlink:to="lab_omc_DelinquentParticipantContributionsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019e9395-5073-734f-ad06-e5f86e80d439_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Domain]</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="lab_us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Statement of Net Asset Available for Benefit [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanStatementOfNetAssetAvailableForBenefitAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_PartyInInterestTransactionsAbstract_label_en-US" xlink:label="lab_omc_PartyInInterestTransactionsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Party-In-Interest Transactions [Abstract]</link:label>
    <link:label id="lab_omc_PartyInInterestTransactionsAbstract_documentation_en-US" xlink:label="lab_omc_PartyInInterestTransactionsAbstract" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Party-In-Interest Transactions [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_PartyInInterestTransactionsAbstract" xlink:href="omc-20251231.xsd#omc_PartyInInterestTransactionsAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_PartyInInterestTransactionsAbstract" xlink:to="lab_omc_PartyInInterestTransactionsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration_019f13b6-1fd6-74db-9030-f9198547ef46_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Description of investment, including maturity date, rate&#160;of&#160;interest, collateral, par or maturity value</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Investment, Current Value, Type [Extensible Enumeration]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentTypeExtensibleEnumeration" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_019efa63-7c80-7636-81d4-42deadcfa06f_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Accounting Policy [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Accounting Policy [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAccountingPolicyLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Tax Status [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentPeriodEndDate_019f1494-6d02-7460-88b2-77fe663f344d_terseLabel_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" 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" 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/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentPeriodEndDate" xlink:to="lab_dei_DocumentPeriodEndDate" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock_019f1444-4f5b-7bbb-b490-5473ce403f47_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Investment</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Investment [Policy Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentType_019e9383-f5d6-7e2f-ba1c-9736bc86e84f_terseLabel_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
    <link:label id="lab_dei_DocumentType_label_en-US" xlink:label="lab_dei_DocumentType" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Type</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentType" xlink:to="lab_dei_DocumentType" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityCentralIndexKey_019f1495-3d68-7a29-865e-438173f93e09_terseLabel_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" 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" 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/2026/dei-2026.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_ValuationTechniqueAxis_019e9395-5073-76d7-91e5-cfa4d65a21e4_terseLabel_en-US" xlink:label="lab_us-gaap_ValuationTechniqueAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Valuation Approach and Technique [Axis]</link:label>
    <link:label id="lab_us-gaap_ValuationTechniqueAxis_label_en-US" xlink:label="lab_us-gaap_ValuationTechniqueAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Valuation Approach and Technique [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ValuationTechniqueAxis" xlink:to="lab_us-gaap_ValuationTechniqueAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_SettlementProceedsTextBlock_019efb22-2cc6-78a4-8c7c-87d9cbda3ef4_terseLabel_en-US" xlink:label="lab_omc_SettlementProceedsTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Settlement Proceeds</link:label>
    <link:label id="lab_omc_SettlementProceedsTextBlock_label_en-US" xlink:label="lab_omc_SettlementProceedsTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Settlement Proceeds [Text Block]</link:label>
    <link:label id="lab_omc_SettlementProceedsTextBlock_documentation_en-US" xlink:label="lab_omc_SettlementProceedsTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Settlement Proceeds</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_SettlementProceedsTextBlock" xlink:href="omc-20251231.xsd#omc_SettlementProceedsTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_SettlementProceedsTextBlock" xlink:to="lab_omc_SettlementProceedsTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds_019efa4b-3b3a-77ca-973a-65978707bc2f_terseLabel_en-US" xlink:label="lab_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Settlement proceeds</link:label>
    <link:label id="lab_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds_label_en-US" xlink:label="lab_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase from Settlement Proceeds</link:label>
    <link:label id="lab_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds_documentation_en-US" xlink:label="lab_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Increase from Settlement Proceeds</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds" xlink:href="omc-20251231.xsd#omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds" xlink:to="lab_omc_EBPChangeInNetAssetAvailableForBenefitIncreaseFromSettlementProceeds" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_019e9368-6603-7b2d-9453-38d1399f4cbf_terseLabel_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Common/Collective Trusts</link:label>
    <link:label id="lab_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember_label_en-US" xlink:label="lab_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Common Collective Trust [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:to="lab_us-gaap_DefinedBenefitPlanCommonCollectiveTrustMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems_019efb1c-5cb3-75ae-8051-7dc3929624a6_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Tax Status [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Tax Status [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems"/>
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    <link:label id="lab_us-gaap-ebp_EbpSubsequentEventTable_019efb23-ab5c-718d-a5d0-e137a5dcdcf6_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EbpSubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Subsequent Event [Table]</link:label>
    <link:label id="lab_us-gaap-ebp_EbpSubsequentEventTable_label_en-US" xlink:label="lab_us-gaap-ebp_EbpSubsequentEventTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Subsequent Event [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpSubsequentEventTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpSubsequentEventTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EbpSubsequentEventTable" xlink:to="lab_us-gaap-ebp_EbpSubsequentEventTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract_019efa4f-bc1c-7253-99fc-9a60ef9a9361_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Deductions:</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Change in Net Asset Available for Benefit, Decrease [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanChangeInNetAssetAvailableForBenefitDecreaseAbstract"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant_019e9371-d792-7415-955c-adb686fd45b5_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Notes receivable from participants</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Note Receivable from Participant</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanNoteReceivableFromParticipant" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_019e9395-5073-7fd6-98ef-1fa311cb9e0d_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Axis]</link:label>
    <link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_label_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value Hierarchy and NAV [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock_019efa59-f436-70a8-ba1d-5c1215ae8e14_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Summary of Significant Accounting Policies</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Summary of Accounting Policy [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanSummaryOfAccountingPolicyTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityRegistrantName_019e9382-46ac-7162-8a97-d53c39c1ff2b_terseLabel_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:label id="lab_dei_EntityRegistrantName_label_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <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_us-gaap-ebp_EbpSubsequentEventAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EbpSubsequentEventAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Subsequent Event [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpSubsequentEventAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpSubsequentEventAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EbpSubsequentEventAbstract" xlink:to="lab_us-gaap-ebp_EbpSubsequentEventAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract_019e937c-0071-7813-a18a-7209143c762b_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Liabilities:</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Liability [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanLiabilityAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock_019efb23-ab5c-75f3-9e28-5fcdcd09a19a_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Subsequent Events</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Subsequent Event [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanSubsequentEventTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock_019efb1d-93e9-7f46-ab99-01f35a5934de_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Schedule of Delinquent Contributions</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable_019efb1d-93e9-7d0a-8d38-d16ae2e09f50_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution [Table]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Schedule of Delinquent Participant Contribution [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanScheduleOfDelinquentParticipantContributionTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock_019efb1c-5cb3-766a-9423-abea818412b3_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Tax Status</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Tax Status [Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanTaxStatusTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis_019e935c-0a17-72e0-8799-d3f394fa96a8_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Allocation Status [Axis]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Allocation Status [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanAllocationStatusAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EbpSubsequentEventLineItems_019efb23-ab5c-75e5-9735-07f4a1b89db7_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EbpSubsequentEventLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Subsequent Event [Line Items]</link:label>
    <link:label id="lab_us-gaap-ebp_EbpSubsequentEventLineItems_label_en-US" xlink:label="lab_us-gaap-ebp_EbpSubsequentEventLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Subsequent Event [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EbpSubsequentEventLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EbpSubsequentEventLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EbpSubsequentEventLineItems" xlink:to="lab_us-gaap-ebp_EbpSubsequentEventLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain_019e935c-0a18-7353-a56b-69b7da9c0d62_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Participant-Directed and Nonparticipant-Directed Status [Domain]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Participant-Directed and Nonparticipant-Directed Status [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis_019e935c-0a18-715e-9ef4-b35a763e94a3_terseLabel_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">EBP, Participant-Directed and Nonparticipant-Directed Status [Axis]</link:label>
    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Participant-Directed and Nonparticipant-Directed Status [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis" xlink:to="lab_us-gaap-ebp_EmployeeBenefitPlanParticipantDirectedStatusAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentInformationTable_019e9383-f5d6-700c-b9af-4fefaa73fbca_terseLabel_en-US" xlink:label="lab_dei_DocumentInformationTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xml:lang="en-US">Document Information [Table]</link:label>
    <link:label id="lab_dei_DocumentInformationTable_label_en-US" xlink:label="lab_dei_DocumentInformationTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Document Information [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Net Asset Available for Benefit</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanNetAssetAvailableForBenefit"/>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairAndContractValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustFairAndContractValue"/>
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    <link:label id="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustContractValue_label_en-US" xlink:label="lab_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustContractValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">EBP, Investment, Excluding Plan Interest in Master Trust, Contract Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustContractValue" xlink:href="https://xbrl.fasb.org/us-gaap/2026/ebp/elts/us-gaap-ebp-2026.xsd#us-gaap-ebp_EmployeeBenefitPlanInvestmentExcludingPlanInterestInMasterTrustContractValue"/>
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    <link:label id="lab_omc_FairValueTextBlock_label_en-US" xlink:label="lab_omc_FairValueTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fair Value [Text Block]</link:label>
    <link:label id="lab_omc_FairValueTextBlock_documentation_en-US" xlink:label="lab_omc_FairValueTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fair Value</link:label>
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