-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 BdRfF+KUd+/sgg3c47DWtduGGud9KuKdNr0k7cwDIxaWVUbxxYi01VTdnX5jqXkr
 b+UWUqepBH1cYUxg/mi6BA==

<SEC-DOCUMENT>0001140361-05-003750.txt : 20050518
<SEC-HEADER>0001140361-05-003750.hdr.sgml : 20050518
<ACCEPTANCE-DATETIME>20050518092523
ACCESSION NUMBER:		0001140361-05-003750
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050516
FILED AS OF DATE:		20050518
DATE AS OF CHANGE:		20050518

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KATY INDUSTRIES INC
		CENTRAL INDEX KEY:			0000054681
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				751277589
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		765 STRAITS TURNPIKE
		STREET 2:		SUITE 2000
		CITY:			MIDDLEBURY
		STATE:			CT
		ZIP:			06762
		BUSINESS PHONE:		2035980397

	MAIL ADDRESS:	
		STREET 1:		765 STRAITS TURNPIKE
		STREET 2:		SUITE 2000
		CITY:			MIDDLEBURY
		STATE:			CT
		ZIP:			06762

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			JACOBI C MICHAEL
		CENTRAL INDEX KEY:			0001194836

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05558
		FILM NUMBER:		05840279

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		2035980397

	MAIL ADDRESS:	
		STREET 1:		C/O KATY INDUSTRIES INC
		STREET 2:		765 STRAITS TURNPIKE STE 2000
		CITY:			MIDDLEBURY
		STATE:			CT
		ZIP:			06762
</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>2005-05-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000054681</issuerCik>
        <issuerName>KATY INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>KT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001194836</rptOwnerCik>
            <rptOwnerName>JACOBI C MICHAEL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>358 TRANQUILITY ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MIDDLEBURY, CT</rptOwnerCity>
            <rptOwnerState>X1</rptOwnerState>
            <rptOwnerZipCode>06762</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>2005-05-16</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2005-05-16</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.66</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>44500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Jacobi has also been granted 1,050,000 options to purchase common stock and 125,000 shares of stock appreciation rights.  Both transactions have been reported on previously filed Form 4s.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael C. Paul as attorney-in-fact for C. Michael Jacobi</signatureName>
        <signatureDate>2005-05-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----