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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2015-07-15</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001639300</issuerCik>
        <issuerName>Ollie's Bargain Outlet Holdings, Inc.</issuerName>
        <issuerTradingSymbol>OLLI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001372939</rptOwnerCik>
            <rptOwnerName>CCMP Capital, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>245 PARK AVENUE, 16TH FL.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10167</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001372942</rptOwnerCik>
            <rptOwnerName>CCMP Capital Investors II, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CCMP CAPITAL, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>245 PARK AVENUE, 16TH FL.</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10167</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001373028</rptOwnerCik>
            <rptOwnerName>CCMP Capital Investors (Cayman) II, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O INTERTRUST CORP SVCS (CAYMAN) LTD</rptOwnerStreet1>
            <rptOwnerStreet2>190 ELGIN AVENUE</rptOwnerStreet2>
            <rptOwnerCity>GEORGE TOWN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-9005</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001372941</rptOwnerCik>
            <rptOwnerName>CCMP Capital Associates, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CCMP CAPITAL, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>245 PARK AVENUE, 16TH FL.</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10167</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001372940</rptOwnerCik>
            <rptOwnerName>CCMP Capital Associates GP, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CCMP CAPITAL, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>245 PARK AVENUE, 16TH FL.</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10167</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.001 per share (&quot;Common Stock&quot;)</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>34603040</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30533305</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4069735</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This Form 3 is being filed in connection with the effectiveness of the Registration Statement on Form S-1 relating to the registration under Section 12 of the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;) of Common Stock of Ollie's Bargain Outlet Holdings, Inc. (the &quot;Issuer&quot;) in connection with the Issuer's initial public offering of such Common Stock.</footnote>
        <footnote id="F2">(Continuation of Footnote 1) - This Form 3 is being filed by (i) CCMP Capital Investors II, L.P. (&quot;CCMP Capital Investors&quot;), (ii) CCMP Capital Investors (Cayman) II, L.P. (&quot;CCMP Cayman&quot; and together with CCMP Capital Investors, the &quot;CCMP Capital Funds&quot;), (iii) CCMP Capital Associates, L.P. (&quot;CCMP Capital Associates&quot;), the general partner of the CCMP Capital Funds, (iv) CCMP Capital Associates GP, LLC (&quot;CCMP Capital Associates GP&quot;), the general partner of CCMP Capital Associates and (v) CCMP Capital, LLC (&quot;CCMP Capital&quot;), the owner of CCMP Capital Associates GP (CCMP Capital, together with the CCMP Capital Funds, CCMP Capital Associates and CCMP Capital Associates GP, the &quot;Reporting Persons&quot;).  The amount of securities indicated in the first row of Table I reflects the aggregate amount of shares beneficially owned by the CCMP Capital Funds.  See footnotes (5) and (6).</footnote>
        <footnote id="F3">(Continuation of Footnote 1) -  Each of CCMP Capital Associates, CCMP Capital Associates GP and CCMP Capital may be deemed, pursuant to Rule 13d-3 under the Exchange Act, to beneficially own the Issuer's common stock reported herein held by the CCMP Capital Funds.  The actual pro rata portion of beneficial ownership of any such shares held by the CCMP Capital Funds that may be deemed attributable to CCMP Capital Associates, CCMP Capital Associates GP and CCMP Capital is not readily determinable because it is subject to several variables, including the internal rate of return within the CCMP Capital Funds.</footnote>
        <footnote id="F4">(Continuation of Footnote 1) - The Reporting Persons disclaim beneficial ownership of the securities to the extent it exceeds their pecuniary interest therein and the inclusion of the shares in this report shall not be deemed to be an admission of beneficial ownership of the reported shares for the purposes of Section 16 of the Exchange Act or otherwise.  The amount shown represents the beneficial ownership of the Issuer's common stock held by the Reporting Persons as a group.  Information with respect to each Reporting Person is given solely by such Reporting Person, and no Reporting Person has responsibility for the accuracy or completeness of information supplied by another Reporting Person.</footnote>
        <footnote id="F5">The amount shown represents the beneficial ownership of shares of the Issuer's Common Stock owned by CCMP Capital Investors II, L.P.</footnote>
        <footnote id="F6">The amount shown represents the beneficial ownership of shares of the Issuer's Common Stock owned by CCMP Capital Investors (Cayman) II, L.P.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>CCMP CAPITAL, LLC By: /s/ Richard G. Jansen, General Counsel</signatureName>
        <signatureDate>2015-07-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>CCMP CAPITAL INVESTORS II, L.P., By: CCMP Capital Associates, L.P., its General Partner, By: CCMP Capital Associates GP, LLC, its general partner, By: /s/ Richard G. Jansen, Managing Director and General Counsel</signatureName>
        <signatureDate>2015-07-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>CCMP CAPITAL INVESTORS (CAYMAN) II, L.P., By: CCMP Capital Associates, L.P., its General Partner, By: CCMP Capital Associates GP, LLC, its general partner, By: /s/ Richard G. Jansen, Managing Director and General Counsel</signatureName>
        <signatureDate>2015-07-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>CCMP CAPITAL ASSOCIATES, L.P., By: CCMP Capital Associates GP, LLC, its general partner, By: /s/ Richard G. Jansen, Managing Director and General Counsel</signatureName>
        <signatureDate>2015-07-15</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>CCMP CAPITAL ASSOCIATES GP, LLC , By: /s/ Richard G. Jansen, Managing Director and General Counsel</signatureName>
        <signatureDate>2015-07-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
