<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019ff254-3f52-72a4-bb67-30f963439903,g:56efc088-323f-4c55-b953-d18a89127c5f-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.stagwellglobal.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="simple" xlink:href="stgw-20260930.xsd#CONSOLIDATEDSTATEMENTSOFOPERATIONS"/>
  <link:calculationLink xlink:role="http://www.stagwellglobal.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_019ff254-41d2-71f5-bd4f-0f0e91fbc909" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019ff254-41d2-748b-8f65-a0c6ae0e2538" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_019ff254-41d2-71f5-bd4f-0f0e91fbc909" xlink:to="loc_us-gaap_OperatingIncomeLoss_019ff254-41d2-748b-8f65-a0c6ae0e2538" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019ff254-41d2-7510-9c8a-5a7194f9cdac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_019ff254-41d2-71f5-bd4f-0f0e91fbc909" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019ff254-41d2-7510-9c8a-5a7194f9cdac" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019ff254-41d2-7724-bb69-b64e2b042dce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDebtExpense_019ff254-41d2-72cc-9bc1-ea4d2d295f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndDebtExpense"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019ff254-41d2-7724-bb69-b64e2b042dce" xlink:to="loc_us-gaap_InterestAndDebtExpense_019ff254-41d2-72cc-9bc1-ea4d2d295f9d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_019ff254-41d2-7770-bb72-ec3e10d9882c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019ff254-41d2-7724-bb69-b64e2b042dce" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_019ff254-41d2-7770-bb72-ec3e10d9882c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019ff254-41d2-716a-a9d7-c258957c729e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019ff254-41d2-7724-bb69-b64e2b042dce" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019ff254-41d2-716a-a9d7-c258957c729e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-7627-98ae-6e01f2dc419e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_IncomeLossFromContinuingOperationsBeforeEquityInEarningsOfNonconsolidatedAffiliates_019ff254-41d2-700b-a80a-e08fe044eeb0" xlink:href="stgw-20260930.xsd#stgw_IncomeLossFromContinuingOperationsBeforeEquityInEarningsOfNonconsolidatedAffiliates"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-7627-98ae-6e01f2dc419e" xlink:to="loc_stgw_IncomeLossFromContinuingOperationsBeforeEquityInEarningsOfNonconsolidatedAffiliates_019ff254-41d2-700b-a80a-e08fe044eeb0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019ff254-41d2-788c-bf9e-c43e577dfabd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-7627-98ae-6e01f2dc419e" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019ff254-41d2-788c-bf9e-c43e577dfabd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ff254-41d2-7bb3-9f41-1b12677b0a19" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-71c5-913e-3c3fc88bf6d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019ff254-41d2-7bb3-9f41-1b12677b0a19" xlink:to="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-71c5-913e-3c3fc88bf6d8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019ff254-41d2-74a5-9820-af4056b60470" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019ff254-41d2-7bb3-9f41-1b12677b0a19" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019ff254-41d2-74a5-9820-af4056b60470" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019ff254-41d2-7e7b-b5da-096cb8a50484" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019ff254-41d2-7f27-86e7-b713818ca07d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpenses"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019ff254-41d2-7e7b-b5da-096cb8a50484" xlink:to="loc_us-gaap_CostsAndExpenses_019ff254-41d2-7f27-86e7-b713818ca07d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019ff254-41d2-759f-b9aa-a7c9e8bde49e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019ff254-41d2-7e7b-b5da-096cb8a50484" xlink:to="loc_us-gaap_Revenues_019ff254-41d2-759f-b9aa-a7c9e8bde49e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_IncomeLossFromContinuingOperationsBeforeEquityInEarningsOfNonconsolidatedAffiliates_019ff254-41d2-7e08-8a65-4ead4745d4e9" xlink:href="stgw-20260930.xsd#stgw_IncomeLossFromContinuingOperationsBeforeEquityInEarningsOfNonconsolidatedAffiliates"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_019ff254-41d2-7e60-b3d7-f40027b9e25c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_stgw_IncomeLossFromContinuingOperationsBeforeEquityInEarningsOfNonconsolidatedAffiliates_019ff254-41d2-7e08-8a65-4ead4745d4e9" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_019ff254-41d2-7e60-b3d7-f40027b9e25c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019ff254-41d2-7e56-8987-856e3e8b6063" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_stgw_IncomeLossFromContinuingOperationsBeforeEquityInEarningsOfNonconsolidatedAffiliates_019ff254-41d2-7e08-8a65-4ead4745d4e9" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019ff254-41d2-7e56-8987-856e3e8b6063" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019ff254-41d2-7687-900e-98fd1499b955" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019ff254-41d2-71b0-8773-9071b59b23ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019ff254-41d2-7687-900e-98fd1499b955" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019ff254-41d2-71b0-8773-9071b59b23ad" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019ff254-41d2-7f83-93c9-72db2f0a2d06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019ff254-41d2-7687-900e-98fd1499b955" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019ff254-41d2-7f83-93c9-72db2f0a2d06" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019ff254-41d2-7bea-929e-6805b901b898" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019ff254-41d2-7687-900e-98fd1499b955" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019ff254-41d2-7bea-929e-6805b901b898" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges_01a17db6-0128-7aa0-bf81-ed89d51bd487" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetImpairmentCharges"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019ff254-41d2-7687-900e-98fd1499b955" xlink:to="loc_us-gaap_AssetImpairmentCharges_01a17db6-0128-7aa0-bf81-ed89d51bd487" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.stagwellglobal.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="simple" xlink:href="stgw-20260930.xsd#CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS"/>
  <link:calculationLink xlink:role="http://www.stagwellglobal.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-77de-b5e7-23abe0be6e60" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-700c-9ae5-7f53f55bf37b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-77de-b5e7-23abe0be6e60" xlink:to="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-700c-9ae5-7f53f55bf37b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019ff254-41d2-72b7-9b66-32b150232dcf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-77de-b5e7-23abe0be6e60" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019ff254-41d2-72b7-9b66-32b150232dcf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019ff254-41d2-76a4-be35-7bd37bb59f25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-7058-b4fe-96e75d60d665" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019ff254-41d2-76a4-be35-7bd37bb59f25" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-7058-b4fe-96e75d60d665" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_019ff254-41d2-7a6e-8c6a-11da571f7d0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019ff254-41d2-76a4-be35-7bd37bb59f25" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_019ff254-41d2-7a6e-8c6a-11da571f7d0f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a17df4-0179-753d-8374-96b387c283b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_01a17df4-0179-7fac-bd57-5a918e82f396" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a17df4-0179-753d-8374-96b387c283b6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_01a17df4-0179-7fac-bd57-5a918e82f396" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_01a17df4-0179-7d34-91dd-7b81e1970b41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_01a17df4-0179-753d-8374-96b387c283b6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax_01a17df4-0179-7d34-91dd-7b81e1970b41" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.stagwellglobal.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="stgw-20260930.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:calculationLink xlink:role="http://www.stagwellglobal.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7455-ace1-e86f22a2846e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_019ff254-41d2-746f-8818-0bc07c32bbe3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7455-ace1-e86f22a2846e" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_019ff254-41d2-746f-8818-0bc07c32bbe3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_AccruedExpensesAndOtherCurrentLiabilities_019ff254-41d2-7aeb-9c30-2b312c2d17bb" xlink:href="stgw-20260930.xsd#stgw_AccruedExpensesAndOtherCurrentLiabilities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7455-ace1-e86f22a2846e" xlink:to="loc_stgw_AccruedExpensesAndOtherCurrentLiabilities_019ff254-41d2-7aeb-9c30-2b312c2d17bb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_019ff254-41d2-7625-8c54-14da9bfae936" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7455-ace1-e86f22a2846e" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityCurrent_019ff254-41d2-7625-8c54-14da9bfae936" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiability_019ff254-41d2-770a-b092-95b04125c27d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiability"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7455-ace1-e86f22a2846e" xlink:to="loc_us-gaap_ContractWithCustomerLiability_019ff254-41d2-770a-b092-95b04125c27d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019ff254-41d2-77d6-a369-a0bb7e122ddf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7455-ace1-e86f22a2846e" xlink:to="loc_us-gaap_AccountsPayableCurrent_019ff254-41d2-77d6-a369-a0bb7e122ddf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_AccruedMediaCostCurrent_019ff254-41d2-7502-8bdd-5ea9ab60a560" xlink:href="stgw-20260930.xsd#stgw_AccruedMediaCostCurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7455-ace1-e86f22a2846e" xlink:to="loc_stgw_AccruedMediaCostCurrent_019ff254-41d2-7502-8bdd-5ea9ab60a560" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019ff254-41d2-7a4d-b478-27a6d7e0248f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-7fdf-b83c-7181d8557ce3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019ff254-41d2-7a4d-b478-27a6d7e0248f" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-7fdf-b83c-7181d8557ce3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityFairValue_019ff254-41d2-71ca-81df-e14bdfd40be5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RedeemableNoncontrollingInterestEquityFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019ff254-41d2-7a4d-b478-27a6d7e0248f" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityFairValue_019ff254-41d2-71ca-81df-e14bdfd40be5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019ff254-41d2-7078-886c-1bce58a6d587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019ff254-41d2-7a4d-b478-27a6d7e0248f" xlink:to="loc_us-gaap_Liabilities_019ff254-41d2-7078-886c-1bce58a6d587" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019ff254-41d2-7c6e-ba5d-54a06ec0fad2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019ff254-41d2-7a4d-b478-27a6d7e0248f" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019ff254-41d2-7c6e-ba5d-54a06ec0fad2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-7b91-954b-5d56b0e0e65b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff254-41d2-70dc-9c62-d485bc64a199" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-7b91-954b-5d56b0e0e65b" xlink:to="loc_us-gaap_StockholdersEquity_019ff254-41d2-70dc-9c62-d485bc64a199" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_019ff254-41d2-7bf9-8df8-9e3047834c62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ff254-41d2-7b91-954b-5d56b0e0e65b" xlink:to="loc_us-gaap_MinorityInterest_019ff254-41d2-7bf9-8df8-9e3047834c62" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7970-8cd4-c7c197dc11e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:to="loc_us-gaap_LiabilitiesCurrent_019ff254-41d2-7970-8cd4-c7c197dc11e4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_019ff254-41d2-74e0-80c9-7be0dba0f8e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_019ff254-41d2-74e0-80c9-7be0dba0f8e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_019ff254-41d2-7ba4-a94c-1a32425cd257" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent_019ff254-41d2-7ba4-a94c-1a32425cd257" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019ff254-41d2-7258-84ef-33aeb751b213" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019ff254-41d2-7258-84ef-33aeb751b213" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome_019ff254-41d2-757e-9ed1-14931032ef6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesTaxDeferredIncome_019ff254-41d2-757e-9ed1-14931032ef6c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_LongTermTaxReceivableAgreementLiability_019ff254-41d2-7506-8f48-fcf5cd026ab6" xlink:href="stgw-20260930.xsd#stgw_LongTermTaxReceivableAgreementLiability"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:to="loc_stgw_LongTermTaxReceivableAgreementLiability_019ff254-41d2-7506-8f48-fcf5cd026ab6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019ff254-41d2-74bb-a5f9-3a9848251dbd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019ff254-41d2-72d3-a120-2431578d369b" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019ff254-41d2-74bb-a5f9-3a9848251dbd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019ff254-41d2-7eee-af4d-def5298ac4f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019ff254-41d2-7b90-81a6-ff28a8ac5239" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019ff254-41d2-7eee-af4d-def5298ac4f9" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019ff254-41d2-7b90-81a6-ff28a8ac5239" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019ff254-41d2-7bdb-b8db-a4d66d81c1eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019ff254-41d2-7eee-af4d-def5298ac4f9" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019ff254-41d2-7bdb-b8db-a4d66d81c1eb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_ExpendituresBillableCurrent_019ff254-41d2-7f39-adc2-2a360512beca" xlink:href="stgw-20260930.xsd#stgw_ExpendituresBillableCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019ff254-41d2-7eee-af4d-def5298ac4f9" xlink:to="loc_stgw_ExpendituresBillableCurrent_019ff254-41d2-7f39-adc2-2a360512beca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_019ff254-41d2-772c-a482-f47752e1a864" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019ff254-41d2-7eee-af4d-def5298ac4f9" xlink:to="loc_us-gaap_OtherAssetsCurrent_019ff254-41d2-772c-a482-f47752e1a864" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ff254-41d2-7432-b18e-f8de7a8889b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValueOutstanding_019ff254-41d2-75cd-8f14-9b1ac0fc9646" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValueOutstanding"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019ff254-41d2-7432-b18e-f8de7a8889b2" xlink:to="loc_us-gaap_CommonStockValueOutstanding_019ff254-41d2-75cd-8f14-9b1ac0fc9646" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019ff254-41d2-7ca9-bb88-6e9740fd4349" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019ff254-41d2-7432-b18e-f8de7a8889b2" xlink:to="loc_us-gaap_CommonStockValue_019ff254-41d2-7ca9-bb88-6e9740fd4349" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019ff254-41d2-7737-8b3e-d317f452fd36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019ff254-41d2-7432-b18e-f8de7a8889b2" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019ff254-41d2-7737-8b3e-d317f452fd36" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019ff254-41d2-7b8a-b3ff-f1278bebf7ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019ff254-41d2-7432-b18e-f8de7a8889b2" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019ff254-41d2-7b8a-b3ff-f1278bebf7ed" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019ff254-41d2-7976-8cc2-2a7278945f6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:to="loc_us-gaap_AssetsCurrent_019ff254-41d2-7976-8cc2-2a7278945f6d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019ff254-41d2-70eb-a273-21e0d9623b7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019ff254-41d2-70eb-a273-21e0d9623b7c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019ff254-41d2-79d1-9e5f-467245eba5b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019ff254-41d2-79d1-9e5f-467245eba5b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ff254-41d2-7308-9617-622f326541df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:to="loc_us-gaap_Goodwill_019ff254-41d2-7308-9617-622f326541df" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019ff254-41d2-7b08-b496-01342be71f53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019ff254-41d2-7b08-b496-01342be71f53" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpense_019ff254-41d2-7df1-b27b-56c5cc427c11" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpense"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpense_019ff254-41d2-7df1-b27b-56c5cc427c11" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019ff254-41d2-7bb5-bac4-c4f3b038c4f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019ff254-41d2-7c5f-9b72-1f81d24adae5" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019ff254-41d2-7bb5-bac4-c4f3b038c4f2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.stagwellglobal.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="stgw-20260930.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:calculationLink xlink:role="http://www.stagwellglobal.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019ff254-41d2-7c8a-a5ab-0ff34b14e3a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7480-a26a-afa7c1b382c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019ff254-41d2-7c8a-a5ab-0ff34b14e3a9" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7480-a26a-afa7c1b382c5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ff254-41d2-7e21-9eeb-b510202b64d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019ff254-41d2-7c8a-a5ab-0ff34b14e3a9" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ff254-41d2-7e21-9eeb-b510202b64d8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7b9b-b778-3e56fca511c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019ff254-41d2-7c8a-a5ab-0ff34b14e3a9" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7b9b-b778-3e56fca511c9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019ff254-41d2-784d-9e53-bf9bc71b633a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019ff254-41d2-7c8a-a5ab-0ff34b14e3a9" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019ff254-41d2-784d-9e53-bf9bc71b633a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit_019ff254-41d2-7942-856b-81329d7fc5b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfLinesOfCredit"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_us-gaap_RepaymentsOfLinesOfCredit_019ff254-41d2-7942-856b-81329d7fc5b3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_019ff254-41d2-76b1-b3b6-097d48f3474e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromLinesOfCredit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_019ff254-41d2-76b1-b3b6-097d48f3474e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019ff254-41d2-7067-b9e6-c953fe58b474" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019ff254-41d2-7067-b9e6-c953fe58b474" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToMinorityShareholders_019ff254-41d2-735d-b0dd-3f6bb83c2cad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToMinorityShareholders"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_us-gaap_PaymentsToMinorityShareholders_019ff254-41d2-735d-b0dd-3f6bb83c2cad" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_PaymentForDeferredContingentConsiderationAndOther_019ff254-41d2-7d8e-b0f5-65684b67e844" xlink:href="stgw-20260930.xsd#stgw_PaymentForDeferredContingentConsiderationAndOther"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_stgw_PaymentForDeferredContingentConsiderationAndOther_019ff254-41d2-7d8e-b0f5-65684b67e844" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsToMinorityShareholders_019ff254-41d2-71b4-9cee-154a7a571636" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromPaymentsToMinorityShareholders"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_us-gaap_ProceedsFromPaymentsToMinorityShareholders_019ff254-41d2-71b4-9cee-154a7a571636" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_TaxReceivablesAgreementPayment_019ff254-41d2-76ba-8291-08627df127cc" xlink:href="stgw-20260930.xsd#stgw_TaxReceivablesAgreementPayment"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_stgw_TaxReceivablesAgreementPayment_019ff254-41d2-76ba-8291-08627df127cc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfFinancingCosts_01a17db8-7866-7fd1-ad49-6b74d33e903b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfFinancingCosts"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019ff254-41d2-7512-9433-44956c33f912" xlink:to="loc_us-gaap_PaymentsOfFinancingCosts_01a17db8-7866-7fd1-ad49-6b74d33e903b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ff254-41d2-7c9d-8075-7bae12153cc0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireSoftware_019ff254-41d2-7c87-981c-cc3d73879d82" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireSoftware"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ff254-41d2-7c9d-8075-7bae12153cc0" xlink:to="loc_us-gaap_PaymentsToAcquireSoftware_019ff254-41d2-7c87-981c-cc3d73879d82" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019ff254-41d2-79bb-8eda-336b5c8f0f56" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ff254-41d2-7c9d-8075-7bae12153cc0" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019ff254-41d2-79bb-8eda-336b5c8f0f56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019ff254-41d2-78ad-ac5d-e6905d550fd9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ff254-41d2-7c9d-8075-7bae12153cc0" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_019ff254-41d2-78ad-ac5d-e6905d550fd9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_019ff254-41d2-7a9d-ae5c-4c9aedfcef92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019ff254-41d2-7c9d-8075-7bae12153cc0" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_019ff254-41d2-7a9d-ae5c-4c9aedfcef92" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-7257-81e5-f0b46ba1fe29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_019ff254-41d2-7257-81e5-f0b46ba1fe29" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019ff254-41d2-7342-9658-0dc015e05b1d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_ShareBasedCompensation_019ff254-41d2-7342-9658-0dc015e05b1d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019ff254-41d2-74a7-ae43-cf9e6c2b35f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019ff254-41d2-74a7-ae43-cf9e6c2b35f7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_019ff254-41d2-7537-86ba-b983998769b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_019ff254-41d2-7537-86ba-b983998769b1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnTerminationOfLease_019ff254-41d2-7f93-b53f-0e693b432da7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnTerminationOfLease"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_GainLossOnTerminationOfLease_019ff254-41d2-7f93-b53f-0e693b432da7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019ff254-41d2-72d4-b950-12d6477c52a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019ff254-41d2-72d4-b950-12d6477c52a3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_AdjustmentToDeferredAcquisitionConsideration_019ff254-41d2-73d7-b1e2-e429b61bfe70" xlink:href="stgw-20260930.xsd#stgw_AdjustmentToDeferredAcquisitionConsideration"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_stgw_AdjustmentToDeferredAcquisitionConsideration_019ff254-41d2-73d7-b1e2-e429b61bfe70" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_019ff254-41d2-7718-a29d-3568e27c8f5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_019ff254-41d2-7718-a29d-3568e27c8f5c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019ff254-41d2-73f3-9612-1e83927586ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019ff254-41d2-73f3-9612-1e83927586ef" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_IncreaseDecreaseInExpendituresBillableToClients_019ff254-41d2-7a96-bda0-25253a469494" xlink:href="stgw-20260930.xsd#stgw_IncreaseDecreaseInExpendituresBillableToClients"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_stgw_IncreaseDecreaseInExpendituresBillableToClients_019ff254-41d2-7a96-bda0-25253a469494" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019ff254-41d2-7b69-8472-47c9cb439d73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019ff254-41d2-7b69-8472-47c9cb439d73" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_stgw_IncreaseDecreaseInAccountsPayableAccruedExpensesAndOtherLiabilities_019ff254-41d2-7d05-bab2-6cae9ad8d0c7" xlink:href="stgw-20260930.xsd#stgw_IncreaseDecreaseInAccountsPayableAccruedExpensesAndOtherLiabilities"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_stgw_IncreaseDecreaseInAccountsPayableAccruedExpensesAndOtherLiabilities_019ff254-41d2-7d05-bab2-6cae9ad8d0c7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_019ff254-41d2-7c38-8612-88b1e051450d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_019ff254-41d2-7c38-8612-88b1e051450d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_019ff254-41d2-760a-8732-669c0eb664aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_019ff254-41d2-760a-8732-669c0eb664aa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019ff254-41d2-7a61-92fc-cfbf9684a66f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_019ff254-41d2-7a61-92fc-cfbf9684a66f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities_019ff254-41d2-7937-b596-a3c91fcd4103" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities"/>
    <link:calculationArc order="16" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019ff254-41d2-7a73-846d-d6c43d6e9a9f" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities_019ff254-41d2-7937-b596-a3c91fcd4103" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.stagwellglobal.com/role/DebtScheduleofDebtDetails" xlink:type="simple" xlink:href="stgw-20260930.xsd#DebtScheduleofDebtDetails"/>
  <link:calculationLink xlink:role="http://www.stagwellglobal.com/role/DebtScheduleofDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019ff254-41d3-7cf0-a549-8b52c97c8dc6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_019ff254-41d3-7410-836d-6ee34a44db4c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019ff254-41d3-7cf0-a549-8b52c97c8dc6" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_019ff254-41d3-7410-836d-6ee34a44db4c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_019ff254-41d3-75e9-8abb-2c742750c0e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019ff254-41d3-7cf0-a549-8b52c97c8dc6" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_019ff254-41d3-75e9-8abb-2c742750c0e3" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
