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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-07-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001132105</issuerCik>
        <issuerName>SPORTSMAN'S WAREHOUSE HOLDINGS, INC.</issuerName>
        <issuerTradingSymbol>SPWH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001702469</rptOwnerCik>
            <rptOwnerName>Barker Jon</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SPORTSMAN'S WAREHOUSE</rptOwnerStreet1>
            <rptOwnerStreet2>1475 WEST 9000 SOUTH SUITE A</rptOwnerStreet2>
            <rptOwnerCity>WEST JORDAN</rptOwnerCity>
            <rptOwnerState>UT</rptOwnerState>
            <rptOwnerZipCode>84088</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-07-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1777.39</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.83</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>472510.91</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21623</value>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Shares Household</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These shares were acquired under the Sportsman's Warehouse Holdings, Inc. Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">Includes 86,589 restricted stock units which are scheduled to vest in three substantially equal installments on March 24, 2021, March 24, 2022, and March 24, 2023, subject to the Reporting Person's continued employment with the Issuer. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.</footnote>
        <footnote id="F3">Includes 31.398 restricted stock units which are scheduled to vest on April 16, 2021, subject to the Reporting Person's continued employment. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.</footnote>
        <footnote id="F4">Includes 12,559 restricted stock units which are scheduled to vest in equal installments on April 16, 2021 and April 16, 2022 subject to the Reporting Person's continued employment. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.</footnote>
        <footnote id="F5">Includes 90,735 restricted stock units which are scheduled to vest in equal installments on April 16, 2021 and April 16, 2022 subject to the Reporting Person's continued employment. Each restricted stock unit represents the right to receive one share of the Issuer's common stock.</footnote>
        <footnote id="F6">Represents shares of the Issuer's common stock held by Karen Seaman with whom the Reporting Person shares a household. The Reporting Person disclaims beneficial ownership of these shares of the Issuer's common stock, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jon Barker</signatureName>
        <signatureDate>2020-07-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
