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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001140361-06-014074.txt : 20061003
<SEC-HEADER>0001140361-06-014074.hdr.sgml : 20061003
<ACCEPTANCE-DATETIME>20061003170735
ACCESSION NUMBER:		0001140361-06-014074
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20061002
FILED AS OF DATE:		20061003
DATE AS OF CHANGE:		20061003

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SONIC CORP
		CENTRAL INDEX KEY:			0000868611
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-EATING PLACES [5812]
		IRS NUMBER:				731371046
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		300 JOHNNY BENCH DRIVE
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73104
		BUSINESS PHONE:		4052255000

	MAIL ADDRESS:	
		STREET 1:		300 JOHNNY BENCH DRIVE
		STREET 2:		4TH FLOOR
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73104

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HUDSON J CLIFFORD
		CENTRAL INDEX KEY:			0001065239
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-EATING PLACES [5812]

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-18859
		FILM NUMBER:		061125597

	BUSINESS ADDRESS:	
		STREET 1:		101 PARK AVENUE
		STREET 2:		STE 1400
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73102-7202
		BUSINESS PHONE:		4052807654

	MAIL ADDRESS:	
		STREET 1:		101 PARK AVE
		STREET 2:		14TH FLOOR
		CITY:			OKLAHOMA CITY
		STATE:			OK
		ZIP:			73102
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-10-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000868611</issuerCik>
        <issuerName>SONIC CORP</issuerName>
        <issuerTradingSymbol>SONC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001065239</rptOwnerCik>
            <rptOwnerName>HUDSON J CLIFFORD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>300 JOHNNY BENCH DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OKLAHOMA CITY</rptOwnerCity>
            <rptOwnerState>OK</rptOwnerState>
            <rptOwnerZipCode>73104</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>2006-10-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>11500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.65</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>503996</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By spouse  as trustee of trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The number of all shares have been adjusted to reflect the three-for-two stock split that occurred April 28, 2006 (an exempt transaction pursuant to Rule 16a-9).</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>J. Clifford Hudson</signatureName>
        <signatureDate>2006-10-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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