-----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,
 DRTSAaMD6p12YBNFnNJpUWT71V4jiqBdUHH8RvFA47hbWbRo9Mi86mrwH8E4S+kh
 HieAS9dblQCmuXxkCzRXNA==

<SEC-DOCUMENT>0001181431-03-010250.txt : 20030723
<SEC-HEADER>0001181431-03-010250.hdr.sgml : 20030723
<ACCEPTANCE-DATETIME>20030606120918
ACCESSION NUMBER:		0001181431-03-010250
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030605
FILED AS OF DATE:		20030606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MATTESON DUNCAN L
		CENTRAL INDEX KEY:			0001189045

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-25034
		FILM NUMBER:		03735365

	BUSINESS ADDRESS:	
		STREET 1:		2860 W BAYSHORE RD
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94303
		BUSINESS PHONE:		6508138200

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GREATER BAY BANCORP
		CENTRAL INDEX KEY:			0000775473
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				770387041
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2860 WEST BAYSHORE ROAD
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94303
		BUSINESS PHONE:		4153751555

	MAIL ADDRESS:	
		STREET 1:		2860 BAYSHORE ROAD
		STREET 2:		420 COWPER ST
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			943011504

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MID PENINSULA BANCORP
		DATE OF NAME CHANGE:	19941031

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SAN MATEO COUNTY BANCORP
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd10644.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-06-05</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000775473</issuerCik>
        <issuerName>GREATER BAY BANCORP</issuerName>
        <issuerTradingSymbol>GBBK</issuerTradingSymbol></issuer>
<reportingOwner>
<reportingOwnerId>
            <rptOwnerCik>0001189045</rptOwnerCik>
            <rptOwnerName>MATTESON DUNCAN L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle></officerTitle>
<otherText></otherText></reportingOwnerRelationship></reportingOwner>
<nonDerivativeSecurity>
<securityTitle>
<value>Common Stock</value></securityTitle>
<transactionDate>
<value>2003-06-05</value></transactionDate>
<transactionCoding>
<transactionFormType>4</transactionFormType>
<transactionCode>G</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F1"/></transactionCoding>
<transactionTimeliness>
<value></value></transactionTimeliness>
<transactionAmounts>
<transactionShares>
<value>30800</value></transactionShares>
<transactionValue>
<value>0</value></transactionValue>
<transactionAcquiredDisposedCode>
<value>D</value></transactionAcquiredDisposedCode></transactionAmounts>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>160000</value></sharesOwnedFollowingTransaction></postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value></directOrIndirectOwnership>
<natureOfOwnership>
<value></value></natureOfOwnership></ownershipNature></nonDerivativeSecurity>
<footnotes>
<footnote id="F1">Bona fide gift.</footnote></footnotes>
<ownerSignature>
<signatureName>Duncan L. Matteson</signatureName>
<signatureDate>2003-06-06</signatureDate></ownerSignature></ownershipDocument>


</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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