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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,
 QZkUub7ID+417JMk5M8CKiPN6gw8WpfgHiD5Iq0mmTYfFw4ekLPmWjlPJ1XEnyDG
 v46u3e3ecfUJVF3CsDFMyw==

<SEC-DOCUMENT>0001246153-03-000009.txt : 20031117
<SEC-HEADER>0001246153-03-000009.hdr.sgml : 20031117
<ACCEPTANCE-DATETIME>20031117124510
ACCESSION NUMBER:		0001246153-03-000009
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031114
FILED AS OF DATE:		20031117

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SCHMAIER R DAVID
		CENTRAL INDEX KEY:			0001238464

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20725
		FILM NUMBER:		031007256

	MAIL ADDRESS:	
		STREET 1:		C/O SIEBEL SYSTEMS INC
		STREET 2:		2207 BRIDGEPOINTE PARKWAY
		CITY:			SAN MATEO
		STATE:			CA
		ZIP:			94404

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SIEBEL SYSTEMS INC
		CENTRAL INDEX KEY:			0001006835
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				943187233
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2207 BRIDGEPOINTE PARKWAY
		CITY:			SAN MATEO
		STATE:			CA
		ZIP:			94404
		BUSINESS PHONE:		6504775000

	MAIL ADDRESS:	
		STREET 1:		2207 BRIDGEPOINTE PARKWAY
		CITY:			SAN MATEO
		STATE:			CA
		ZIP:			94404
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001238464d20031114f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-11-14</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0001006835</issuerCik><issuerName>SIEBEL SYSTEMS INC</issuerName>        <issuerTradingSymbol>SEBL</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001238464</rptOwnerCik><rptOwnerName>SCHMAIER R DAVID</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>C/O SIEBEL SYSTEMS, INC.</rptOwnerStreet1><rptOwnerStreet2>2207 BRIDGEPOINTE PARKWAY</rptOwnerStreet2><rptOwnerCity>SAN MATEO</rptOwnerCity><rptOwnerState>CA</rptOwnerState><rptOwnerZipCode>94404</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Executive Vice President</officerTitle><otherText></otherText></reportingOwner
Relationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-11-14</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>42857</value></transactionShares><transactionPricePerShare><value>0.18</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>423586</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></nonDeriva
tiveTransaction><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2842</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Son</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2842</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Daughter</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Stock Options (Right to buy)</value></securityTitle><conversionOrExercisePrice><value>0.18</value></conversionO
rExercisePrice><transactionDate><value>2003-11-14</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>42857</value></transactionShares><transactionPricePerShare><value>0.1812</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>1998-06-02</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2006-03-24</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>42857</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>85714</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOr
IndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Option becomes exercisable at a rate of 3.57% each quarter after March 2, 1998.</footnote></footnotes><ownerSignature><signatureName>R. D Schmaier</signatureName><signatureDate>2003-11-14</signatureDate></ownerSignature></ownershipDocument>

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</TEXT>
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</SEC-DOCUMENT>
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