<SEC-DOCUMENT>0000824142-20-000071.txt : 20200413
<SEC-HEADER>0000824142-20-000071.hdr.sgml : 20200413
<ACCEPTANCE-DATETIME>20200413123812
ACCESSION NUMBER:		0000824142-20-000071
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200401
FILED AS OF DATE:		20200413
DATE AS OF CHANGE:		20200413

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Stewart Larry Gene
		CENTRAL INDEX KEY:			0001809015

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18953
		FILM NUMBER:		20788288

	MAIL ADDRESS:	
		STREET 1:		2425 SOUTH YUKON AVE
		CITY:			TULSA
		STATE:			OK
		ZIP:			74107

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AAON, INC.
		CENTRAL INDEX KEY:			0000824142
		STANDARD INDUSTRIAL CLASSIFICATION:	AIR COND & WARM AIR HEATING EQUIP & COMM & INDL REFRIG EQUIP [3585]
		IRS NUMBER:				870448736
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2425 SOUTH YUKON AVE.
		CITY:			TULSA
		STATE:			OK
		ZIP:			74107
		BUSINESS PHONE:		9185832266

	MAIL ADDRESS:	
		STREET 1:		2425 SOUTH YUKON AVE.
		CITY:			TULSA
		STATE:			OK
		ZIP:			74107

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AAON INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DIAMOND HEAD RESOURCES INC
		DATE OF NAME CHANGE:	19900808
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>wf-form3_158679587462890.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-04-01</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000824142</issuerCik>
        <issuerName>AAON, INC.</issuerName>
        <issuerTradingSymbol>AAON</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001809015</rptOwnerCik>
            <rptOwnerName>Stewart Larry Gene</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2425 S. YUKON AVE.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TULSA</rptOwnerCity>
            <rptOwnerState>OK</rptOwnerState>
            <rptOwnerZipCode>74107</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $.004</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>970</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>46.88</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2021-04-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2030-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>14390.0</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This restricted stock award is granted under the Issuer's 2016 Long Term Incentive Plan and vests ratably on each of the first five anniversaries of the date of the grant (date of grant, April 1, 2020).</footnote>
        <footnote id="F2">This stock option award is granted under the Issuer's 2016 Long Term Incentive Plan and is exercisable ratably on each of the first five anniversaries of the date of the grant (date of grant, April 1, 2020).</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Larry G. Stewart</signatureName>
        <signatureDate>2020-04-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
