<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-10-14</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001334978</issuerCik>
        <issuerName>Clear Channel Outdoor Holdings, Inc.</issuerName>
        <issuerTradingSymbol>CCO</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001682494</rptOwnerCik>
            <rptOwnerName>White Raymond T.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>12121 WILSHIRE BLVD.</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1240</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001560207</rptOwnerCik>
            <rptOwnerName>Legion Partners Asset Management, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>12121 WILSHIRE BLVD., SUITE 1240</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001682389</rptOwnerCik>
            <rptOwnerName>Legion Partners Holdings, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>12121 WILSHIRE BLVD., SUITE 1240</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001432744</rptOwnerCik>
            <rptOwnerName>Kiper Christopher S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>12121 WILSHIRE BLVD, SUITE 1240</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2026-10-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>91003</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.4300</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4 is filed jointly by Legion Partners Asset Management, LLC (&quot;Legion Partners Asset Management&quot;), Legion Partners Holdings, LLC (&quot;Legion Partners Holdings&quot;), Raymond T. White and Christopher S. Kiper (collectively, the &quot;Reporting Persons&quot;). Each Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his or its pecuniary interest therein, and this report shall not be deemed to be an admission that any Reporting Person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.</footnote>
        <footnote id="F2">Pursuant to the Agreement and Plan of Merger, dated as of February 9, 2026 (the &quot;Merger Agreement&quot;), whereby Madison Merger Sub Inc., a wholly-owned subsidiary of Madison Parent Inc. (&quot;Parent&quot;), merged with and into the Issuer (the &quot;Merger&quot;) with the Issuer surviving as a wholly-owned subsidiary of Parent, each share of the Issuer's common stock (&quot;Common Stock&quot;) outstanding immediately prior to the effective time of the Merger was converted into the right to receive an amount in cash equal to $2.43 per share, and each outstanding award of restricted stock units (&quot;RSUs&quot;) of the Issuer was cancelled and converted into the right to receive an amount in cash amount equal to $2.43 multiplied by the total number of shares subject to such award (the &quot;RSU Consideration&quot;).</footnote>
        <footnote id="F3">Pursuant to the Merger Agreement, each award of RSUs issued in lieu of cash retainers outstanding immediately prior to the effective time of the Merger was converted into the RSU Consideration with respect to a pro rata portion of the shares of Common Stock subject to such award.</footnote>
        <footnote id="F4">Mr. White served on the Board of the Issuer as a representative of Legion Partners Asset Management and its affiliates. Mr. White did not have a right to any economic interest in securities of the Issuer granted to him by the Issuer in respect of his Board position, except to the extent of his role as a Managing Director of Legion Partners Asset Management. Legion Partners Asset Management is entitled to receive all of the economic interest in securities granted to Mr. White by the Issuer in respect of Mr. White's Board position. Mr. White disclaims beneficial ownership of the Issuer's securities to which this report relates and at no time has Mr. White had any economic interest in such securities except any indirect economic interest through Legion Partners Asset Management and its affiliates, entities in which Mr. White has a controlling interest and investment control.</footnote>
        <footnote id="F5">The securities described in footnotes (4) and (5) represent securities in which Legion Partners Asset Management had all of the direct economic interest. Legion Partners Holdings is the sole member of Legion Partners Asset Management and each of Messrs. Kiper and White are Managing Directors of Legion Partners Asset Management. As a result of these relationships, Legion Partners Holdings and Messrs. Kiper and White may be deemed to beneficially own the securities owned directly by Legion Partners Asset Management.</footnote>
    </footnotes>

    <remarks>Raymond T. White, a managing director of Legion Partners Asset Management, was a director of the Issuer. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each of the Reporting Persons (other than Mr. White) may be deemed a director by deputization by virtue of its or his representation on the Board of Directors of the Issuer.</remarks>

    <ownerSignature>
        <signatureName>/s/ Raymond T. White</signatureName>
        <signatureDate>2026-10-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Legion Partners Asset Management, LLC, By: /s/ Raymond T. White, Managing Member</signatureName>
        <signatureDate>2026-10-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Legion Partners Holdings, LLC, By: /s/ Raymond T. White, Managing Member</signatureName>
        <signatureDate>2026-10-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Christopher S. Kiper</signatureName>
        <signatureDate>2026-10-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
