-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 F7DINeiUjZ/6BZ22ZORviQ3aYi2NrAMf6lTnF+KZniwlujJelrog00+RRL95AEsY
 wTzg29kWHqToQ21xQ3RbbA==

<SEC-DOCUMENT>0001140361-03-003449.txt : 20030922
<SEC-HEADER>0001140361-03-003449.hdr.sgml : 20030922
<ACCEPTANCE-DATETIME>20030922105637
ACCESSION NUMBER:		0001140361-03-003449
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030918
FILED AS OF DATE:		20030922

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VALERIUS STEVEN P
		CENTRAL INDEX KEY:			0001203126

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07615
		FILM NUMBER:		03903599

	BUSINESS ADDRESS:	
		STREET 1:		55 WAUGH DRIVE
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77007

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KIRBY CORP
		CENTRAL INDEX KEY:			0000056047
		STANDARD INDUSTRIAL CLASSIFICATION:	WATER TRANSPORTATION [4400]
		IRS NUMBER:				741884980
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		55 WAUGH DRIVE SUITE 1000
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77385
		BUSINESS PHONE:		7134351000

	MAIL ADDRESS:	
		STREET 1:		P.O. BOX 1745
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77251

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KIRBY EXPLORATION CO INC
		DATE OF NAME CHANGE:	19900510
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-09-18</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000056047</issuerCik>
        <issuerName>KIRBY CORP</issuerName>
        <issuerTradingSymbol>KEX</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001203126</rptOwnerCik>
            <rptOwnerName>VALERIUS STEVEN P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>55 WAUGH DRIVE, SUITE 1000</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77007</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>Pres. Kirby Inland Marine, LP</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable>
<nonDerivativeHolding>
<securityTitle>
<value>Common Stock, par value $.10 per share</value>
</securityTitle>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>10447</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeHolding>
<nonDerivativeHolding>
<securityTitle>
<value>Common Stock, par value $.10 per share</value>
</securityTitle>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>695</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value>401(k) Plan</value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeHolding>
<nonDerivativeHolding>
<securityTitle>
<value>Common Stock, par value $.10 per share</value>
</securityTitle>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>463</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value>401(k) Plan</value>
<footnoteId id="F1"/>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeHolding>
</nonDerivativeTable>
<derivativeTable>
<derivativeTransaction>
<securityTitle>
<value>Employee Stock Option (Right to Buy)</value>
</securityTitle>
<conversionOrExercisePrice>
<value>19.0625</value>
</conversionOrExercisePrice>
<transactionDate>
<value>2003-09-18</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F2"/>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>1500</value>
</transactionShares>
<transactionPricePerShare>
<value>19.0625</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate>
<value>2003-10-19</value>
<footnoteId id="F3"/>
</exerciseDate>
<expirationDate>
<value>2009-10-19</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>1500</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>104016</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeTransaction>
<derivativeTransaction>
<securityTitle>
<value>Employee Stock Option (Right to Buy)</value>
</securityTitle>
<conversionOrExercisePrice>
<value>19.0625</value>
</conversionOrExercisePrice>
<transactionDate>
<value>2003-09-19</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F4"/>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>3500</value>
</transactionShares>
<transactionPricePerShare>
<value>19.0625</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate>
<value>2003-10-19</value>
<footnoteId id="F3"/>
</exerciseDate>
<expirationDate>
<value>2009-10-19</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>3500</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>100516</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeTransaction>
<derivativeTransaction>
<securityTitle>
<value>Employee Stock Option (Right to Buy)</value>
</securityTitle>
<conversionOrExercisePrice>
<value>21.5313</value>
</conversionOrExercisePrice>
<transactionDate>
<value>2003-09-19</value>
</transactionDate>
<deemedExecutionDate>
</deemedExecutionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F4"/>
</transactionCoding>
<transactionTimeliness>
<value></value>
</transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>5000</value>
</transactionShares>
<transactionPricePerShare>
<value>21.5313</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode>
<value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate>
<value>2004-01-15</value>
<footnoteId id="F5"/>
</exerciseDate>
<expirationDate>
<value>2006-01-15</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>5000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>95516</value>
<footnoteId id="F6"/>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeTransaction>
</derivativeTable>
<footnotes>
<footnote id="F1">Shares owned beneficially  and of record by Mr. Valerius&#039; wife, through the Kirby Corporation 401(k) Plan.  Mr. Valerius disclaims ownership of the shares.</footnote>
<footnote id="F2">Mr. Valerius exercised an option for 1,500 shares on September 18, 2003 and, of the exercise, 1,500 shares were registered in the name of his ex-wife, Marcia Lynn Harris, pursuant to a domestic relations order.</footnote>
<footnote id="F3">Original option of 40,000 shares exercisable 25% after one year, 50% after two years, 75% after three years and 100% after four years from date of grant.</footnote>
<footnote id="F4">Mr. Valerius exercised options totaling 8,500 shares on September 19, 2003 and, of the exercise, 8,500 shares were registered in the name of his ex-wife, Marcia Lynn Harris, pursuant to a domestic relations order.</footnote>
<footnote id="F5">Original option of 30,000 shares exercisable 33% after one year, 67% after two years and 100% after three years from date of grant.</footnote>
<footnote id="F6">Also, options of 23,834 shares are owned by record by Mr. Valerius&#039; wife through various Kirby Corporation Employee Stock Option Plans.  Mr. Valerius disclaims beneficial ownership of the option shares.</footnote>
</footnotes>
<remarks></remarks>
<ownerSignature>
<signatureName>Steven P. Valerius</signatureName>
<signatureDate>2003-09-22</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
