<SEC-DOCUMENT>0001047469-18-002768-index.html : 20180413
<SEC-HEADER>0001047469-18-002768.hdr.sgml : 20180413
<ACCEPTANCE-DATETIME>20180413060040
ACCESSION NUMBER:		0001047469-18-002768
CONFORMED SUBMISSION TYPE:	DEF 14A
PUBLIC DOCUMENT COUNT:		4
CONFORMED PERIOD OF REPORT:	20180515
FILED AS OF DATE:		20180413
DATE AS OF CHANGE:		20180413
EFFECTIVENESS DATE:		20180413

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:		DEF 14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-10537
		FILM NUMBER:		18753078

	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>DEF 14A
<SEQUENCE>1
<FILENAME>a2235176zdef14a.htm
<DESCRIPTION>DEF 14A
<TEXT>
Document 1 - file: a2235176zdef14a.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g72535.jpg
<DESCRIPTION>G72535.JPG
<TEXT>
Document 2 - file: g72535.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g29593cai001.gif
<DESCRIPTION>G29593CAI001.GIF
<TEXT>
Document 3 - file: g29593cai001.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g29593cai002.gif
<DESCRIPTION>G29593CAI002.GIF
<TEXT>
Document 4 - file: g29593cai002.gif

</DOCUMENT>
</SEC-DOCUMENT>