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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-09-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001552800</issuerCik>
        <issuerName>TILE SHOP HOLDINGS, INC.</issuerName>
        <issuerTradingSymbol>TTS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001555414</rptOwnerCik>
            <rptOwnerName>NABRON INTERNATIONAL INC.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2ND FLOOR, LE PRINCE DE GALLES</rptOwnerStreet1>
            <rptOwnerStreet2>3-5 AVENUE DES CITRONNIERS</rptOwnerStreet2>
            <rptOwnerCity>MONACO</rptOwnerCity>
            <rptOwnerState>O9</rptOwnerState>
            <rptOwnerZipCode>MC98000</rptOwnerZipCode>
            <rptOwnerStateDescription>MONACO</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-09-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2469</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.35</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10525537</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Raymond Long Sing Tang, Lars Soren Sorensen, and Louise Mary Garbarino are the directors of the reporting person and exercise voting and investment power over these securities. The reporting person and each of its directors disclaim beneficial ownership of these securities except to the extent of their respective pecuniary interests therein, and this report shall not be deemed an admission that the reporting person or any of its directors is the beneficial owner of such securities for Section 16 or any other purpose.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Paul D. Broude by Power of Attorney</signatureName>
        <signatureDate>2014-09-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
