<SEC-DOCUMENT>0000824142-19-000020.txt : 20190131
<SEC-HEADER>0000824142-19-000020.hdr.sgml : 20190131
<ACCEPTANCE-DATETIME>20190131173233
ACCESSION NUMBER:		0000824142-19-000020
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190124
FILED AS OF DATE:		20190131
DATE AS OF CHANGE:		20190131

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lawhorn Caron A
		CENTRAL INDEX KEY:			0001302089

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18953
		FILM NUMBER:		19556876

	MAIL ADDRESS:	
		STREET 1:		100 WEST FIFTH STREET
		CITY:			TULSA
		STATE:			OK
		ZIP:			74103

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
		CITY:			TULSA
		STATE:			OK
		ZIP:			74107
		BUSINESS PHONE:		9185832266

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

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DIAMOND HEAD RESOURCES INC
		DATE OF NAME CHANGE:	19900808
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>wf-form3_154897393483857.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2019-01-24</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001302089</rptOwnerCik>
            <rptOwnerName>Lawhorn Caron A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>15 E. 5TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TULSA</rptOwnerCity>
            <rptOwnerState>OK</rptOwnerState>
            <rptOwnerZipCode>74103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Caron A. Lawhorn</signatureName>
        <signatureDate>2019-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
