<SEC-DOCUMENT>0001047469-17-004979-index.html : 20170804
<SEC-HEADER>0001047469-17-004979.hdr.sgml : 20170804
<ACCEPTANCE-DATETIME>20170804073851
ACCESSION NUMBER:		0001047469-17-004979
CONFORMED SUBMISSION TYPE:	S-3
PUBLIC DOCUMENT COUNT:		8
FILED AS OF DATE:		20170803
DATE AS OF CHANGE:		20170804

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OLD SECOND BANCORP INC
		CENTRAL INDEX KEY:			0000357173
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				363143493
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1215

	FILING VALUES:
		FORM TYPE:		S-3
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-219680
		FILM NUMBER:		171006903

	BUSINESS ADDRESS:	
		STREET 1:		37 S RIVER ST
		CITY:			AURORA
		STATE:			IL
		ZIP:			60507
		BUSINESS PHONE:		6308920202

	MAIL ADDRESS:	
		STREET 1:		37 SOUTH RIVER STREET
		CITY:			AURORA
		STATE:			IL
		ZIP:			60507
</SEC-HEADER>
<DOCUMENT>
<TYPE>S-3
<SEQUENCE>1
<FILENAME>a2232881zs-3.htm
<DESCRIPTION>S-3
<TEXT>
Document 1 - file: a2232881zs-3.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-4.13
<SEQUENCE>2
<FILENAME>a2232881zex-4_13.htm
<DESCRIPTION>EX-4.13
<TEXT>
Document 2 - file: a2232881zex-4_13.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>3
<FILENAME>a2232881zex-5_1.htm
<DESCRIPTION>EX-5.1
<TEXT>
Document 3 - file: a2232881zex-5_1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-12.1
<SEQUENCE>4
<FILENAME>a2232881zex-12_1.htm
<DESCRIPTION>EX-12.1
<TEXT>
Document 4 - file: a2232881zex-12_1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>5
<FILENAME>a2232881zex-23_1.htm
<DESCRIPTION>EX-23.1
<TEXT>
Document 5 - file: a2232881zex-23_1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-25.1
<SEQUENCE>6
<FILENAME>a2232881zex-25_1.htm
<DESCRIPTION>EX-25.1
<TEXT>
Document 6 - file: a2232881zex-25_1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>g188442kmi001.gif
<DESCRIPTION>G188442KMI001.GIF
<TEXT>
Document 7 - file: g188442kmi001.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>8
<FILENAME>g502868.jpg
<DESCRIPTION>G502868.JPG
<TEXT>
Document 8 - file: g502868.jpg

</DOCUMENT>
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