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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2015-06-24</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001637913</issuerCik>
        <issuerName>Milacron Holdings Corp.</issuerName>
        <issuerTradingSymbol>MCRN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001463559</rptOwnerCik>
            <rptOwnerName>Her Majesty the Queen in Right of the Province of Alberta as represented by Alberta Investment Management Corp</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1100-10830 JASPER AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>EDMONTON</rptOwnerCity>
            <rptOwnerState>A0</rptOwnerState>
            <rptOwnerZipCode>T5J 2B3</rptOwnerZipCode>
            <rptOwnerStateDescription>ALBERTA, CANADA</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 $0.01 per share (&quot;Common Stock&quot;)</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7972499</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The securities are held directly by PE12GVPE (Talon) Ltd. (3,751,858 shares) and PE12PXPE (Talon) Ltd. (4,220,641 shares). Alberta Investment Management Corporation (&quot;AIMCo&quot;) may be deemed to have voting and investment power with respect to shares held by PE12GVPE (Talon) Ltd. and PE12PXPE (Talon) Ltd. AIMCo disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of the Issuer's shares reported herein in which AIMCo has no actual pecuniary interest.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Alberta Investment Management Corporation, By:  /s/ Brett Kiriak, Chief Compliance Officer</signatureName>
        <signatureDate>2015-06-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
