FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Pilmer Donald   2. Issuer Name and Ticker or Trading Symbol OLD SECOND BANCORP INC [OSBC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP (Last) (First) (Middle) 37 S. RIVER ST. 3. Date of Earliest Transaction (Month/Day/Year) 03/30/2018 (Street) AURORA, IL 60506 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Old Second Bancorp, Inc. Common Stock 03/30/2018   A   61 A (2) 2,715 (4) I 401(k) plan Old Second Bancorp, Inc. Common Stock               46,408.054 (3) D   Old Second Bancorp, Inc. Common Stock               924 I Profit Sharing Plan Old Second Bancorp, Inc. Common Stock               1,450 (1) I Spouse's IRA

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Pilmer Donald 37 S. RIVER ST. AURORA, IL 60506			EVP

Signatures

/s/ Donald Pilmer		03/30/2018
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	These shares are held in spouse's IRA for which Mr. Pilmer is listed as a beneficiary.
(2)	Does not apply.
(3)	Included in this total are 10,257 shares held in Mr. Pilmer's name alone; 12,549 shares held in brokerage; 23,566 shares of Restricted Stock Units and 36.054 shares of Restricted Stock Equivalents.
(4)	Of this total, 61 shares were allocated during the first quarter pursuant to the Old Second Bancorp, Inc. Employee Savings Plan. Information herein was provided by the Plan Trustee as of 3-30-18.

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