Ownership Submission
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 *
BENOIST PETER
  2. Issuer Name and Ticker or Trading Symbol
ENTERPRISE FINANCIAL SERVICES CORP [EFSC]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
President & CEO
(Last)
(First)
(Middle)
150 N. MERAMEC
3. Date of Earliest Transaction (Month/Day/Year)
12/15/2011
(Street)

ST. LOUIS, MO 63105
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
Common Stock 12/15/2011   M   1,322 A $ 0 13,297 D  
Common Stock 12/15/2011   F   429 D $ 15 12,868 D  
Common Stock               1,377 I 401 (k) Plan (1)
Common Stock               23,168 I By Trust
Common Stock               140,460 D (2)  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
Restricted Share Units (3) 12/15/2011   M     1,322   (4)   (4) Common Stock 1,322 $ 0 0 D  
Incentive Stock Option (Right to Buy) $ 10.25             10/01/2001(5) 10/01/2012 Common Stock 50,000   50,000 D  
Non Qualified Stock Option (Right to Buy) $ 13.4             10/01/2004(5) 05/13/2013 Common Stock 37,313   37,313 D  
Non Qualified Stock Option (Right to Buy) $ 22.73             01/05/2009(6) 01/05/2016 Common Stock 3,850   3,850 D  
Non Qualified Stock Option (Right to Buy) $ 30.17             01/05/2010(6) 01/05/2017 Common Stock 2,900   2,900 D  
Non Qualified Stock Option (Right to Buy) $ 22.9             01/05/2011(6) 01/05/2018 Common Stock 3,970   3,970 D  
Stock Settled Stock Appreciation Rights $ 25.63             12/15/2007(7) 06/15/2017 Common Stock 16,508   16,508 D  
Stock Settled Stock Appreciation Rights $ 20.63             12/15/2008(8) 06/13/2018 Common Stock 43,178   43,178 D  
Stock Settled Stock Appreciation Rights $ 21.49             09/24/2009(9) 09/24/2018 Common Stock 50,000   50,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BENOIST PETER
150 N. MERAMEC
ST. LOUIS, MO 63105
  X     President & CEO  

Signatures

 /s/ Peter Benoist   12/16/2011
**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) The reporting person holds units in the stock fund and the number of shares reported as indirectly held in the 401 (k) plan in this row is an estimate of the number of shares of the issuer's Common Stock held in the unitized stock fund and allocated to the reporting person's account.
(2) Held Jointly with Spouse
(3) The RSUs were granted pursuant to the Company's 2002 Stock Incentive Plan. Each RSU represents the right to receive one share of Common Stock, subject to adjustment as provided in the Grant Agreement.
(4) The RSUs vest at a rate of 20% annually over five years, subject to continued employment of the reporting person. Vesting occurs on December 15 of each year, commencing in the calendar year of the grant. On each vesting date, for each RSU vesting on such date, the reporting person will receive one share of Common Stock.
(5) Effective 10/01/2004 the Board fully vested the oustanding employee and Director stock options.
(6) Options vest 33% per year for three years
(7) Each SSAR consists of the right to receive an amount, in common stock, equal to the excess of the fair market value of a share of common stock on the date of exercise over the exercise price of the SSAR. The SSARs vest at a rate of 20% annually over five years, subject to continued employement of the reporting person. Vesting occurs on December 15 of each year, commencing December 15, 2007.
(8) Each SSAR consists of the right to receive an amount, in common stock, equal to the excess of the fair market value of a share of common stock on the date of exercise over the exercise price of the SSAR. The SSARs vest at a rate of 20% annually over five years, subject to continued employment of the reporting person. Vesting occurs on December 15 of each year, commencing December 15, 2008.
(9) Each SSAR consists of the right to receive an amount, in common stock, equal to the excess of the fair market value of a share of common stock on the date of exercise over the exercise price of the SSAR. The SSARs vest at a rate of 33% annually over three years, subject to continued employment of the reporting person. Vesting occurs on September 24 of each year, commencing September 24, 2009.

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