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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2020-05-27</periodOfReport>

    <dateOfOriginalSubmission>2020-05-29</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001456330</rptOwnerCik>
            <rptOwnerName>WELLS SCOTT</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CLEAR CHANNEL OUTDOOR HOLDINGS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>4830 NORTH LOOP 1604W, SUITE 111</rptOwnerStreet2>
            <rptOwnerCity>SAN ANTONIO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78249</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP and CEO - Americas</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>867356</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On May 29, 2020, the reporting person filed a Form 4 which inadvertently reported that, following purchases of the issuer's common stock on May 27, 2020, the reporting person directly owned 348,600 shares of common stock, and following purchases of the issuer's common stock on May 28, 2020, the reporting person directly owned 368,600 shares of common stock. In fact, as reported in this amendment, the reporting person directly owned 867,356 shares of common stock as of May 28, 2020.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Lynn A. Feldman, as Attorney-in-fact on behalf of Scott Wells</signatureName>
        <signatureDate>2020-09-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
