-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 aAXJwKEQfxOKBiNIG5BN9A==

<SEC-DOCUMENT>0001181007-08-000002.txt : 20080527
<SEC-HEADER>0001181007-08-000002.hdr.sgml : 20080526
<ACCEPTANCE-DATETIME>20080527114313
ACCESSION NUMBER:		0001181007-08-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080520
FILED AS OF DATE:		20080527
DATE AS OF CHANGE:		20080527

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ATMOS ENERGY CORP
		CENTRAL INDEX KEY:			0000731802
		STANDARD INDUSTRIAL CLASSIFICATION:	NATURAL GAS DISTRIBUTION [4924]
		IRS NUMBER:				751743247
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		1800 THREE LINCOLN CTR
		STREET 2:		5430 LBJ FREEWAY
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75240
		BUSINESS PHONE:		9729349227

	MAIL ADDRESS:	
		STREET 1:		1800 THREE LINCOLN CTR
		STREET 2:		5430 LBJ FREEWAY
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75240

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ENERGAS CO
		DATE OF NAME CHANGE:	19881024

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SCHLESSMAN LEE E
		CENTRAL INDEX KEY:			0001181007

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10042
		FILM NUMBER:		08859862

	BUSINESS ADDRESS:	
		STREET 1:		ATMOS ENERGY CORP
		STREET 2:		P O BOX 650205
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75265
		BUSINESS PHONE:		9728553718
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-05-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000731802</issuerCik>
        <issuerName>ATMOS ENERGY CORP</issuerName>
        <issuerTradingSymbol>ATO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181007</rptOwnerCik>
            <rptOwnerName>SCHLESSMAN LEE E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5430 LBJ FREEWAY</rptOwnerStreet1>
            <rptOwnerStreet2>1800 III LINCOLN CENTRE</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75240</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Honorary Director</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>32929.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>243539.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>32929.00</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>625668.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <ownerSignature>
        <signatureName>Dwala Kuhn by POA</signatureName>
        <signatureDate>2008-05-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----