Sec Form 4 Filing - Case Gregory C @ Aon plc - 2015-02-13

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 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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1. Name and Address of Reporting Person Case Gregory C 2. Issuer Name and Ticker or Trading Symbol Aon plc [ AON] 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) AON CORPORATION - CORPORATE LAW DEPT, 200 EAST RANDOLPH STREET, 8TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 02/13/2015 (Street) CHICAGO, IL60601 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 Class A Ordinary Shares 02/13/2015 M( 1 ) 50,000 A $ 22.86 838,295 D Class A Ordinary Shares 02/13/2015 S( 1 ) 29,001 D $ 101.107 ( 2 ) 809,294 D Class A Ordinary Shares 02/14/2015 M( 3 ) 4,312 A 813,606 D Class A Ordinary Shares 02/14/2015 F( 4 ) 1,971 D $ 100.56 811,635 D Class A Ordinary Shares 02/15/2015 M( 3 ) 6,038 A 817,673 D Class A Ordinary Shares 02/15/2015 F( 4 ) 2,760 D $ 100.56 814,913 D Class A Ordinary Shares 02/17/2015 M( 1 ) 50,000 A $ 22.86 864,913 D Class A Ordinary Shares 02/17/2015 S( 1 ) 29,012 D $ 100.62 ( 5 ) 835,901 D Class A Ordinary Shares 02/17/2015 M( 3 ) 4,899 A 840,800 D Class A Ordinary Shares 02/17/2015 F( 4 ) 2,239 D $ 100.71 838,561 D Class A Ordinary Shares 02/18/2015 M( 1 ) 50,000 A $ 22.86 888,561 D Class A Ordinary Shares 02/18/2015 S( 1 ) 29,049 D $ 100.589 ( 6 ) 859,512 D Class A Ordinary Shares 176,000 I By Trust

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Employee Stock Option (Right to Buy) $ 22.86 02/13/2015 M 50,000 ( 7 ) 04/04/2015 Class A Ordinary Shares 50,000 ( 8 ) 950,000 D Restricted Share Unit (Right to Receive) ( 9 ) 02/14/2015 M 4,312 02/14/2015( 10 ) 02/14/2017 Class A Ordinary Shares 4,312 $ 0 8,624 D Restricted Share Unit (Right to Receive) ( 9 ) 02/15/2015 M 6,038 02/15/2014( 10 ) 02/15/2016 Class A Ordinary Shares 6,038 $ 0 6,038 D Employee Stock Option (Right to Buy) $ 22.86 02/17/2015 M 50,000 ( 7 ) 04/04/2015 Class A Ordinary Shares 50,000 ( 8 ) 900,000 D Restricted Share Unit (Right to Receive) ( 9 ) 02/17/2015 M 4,899 02/17/2013( 10 ) 02/17/2015 Class A Ordinary Shares 4,899 $ 0 0 D Employee Stock Option (Right to Buy) $ 22.86 02/18/2015 M 50,000 ( 7 ) 04/04/2015 Class A Ordinary Shares 50,000 ( 8 ) 850,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Case Gregory C AON CORPORATION - CORPORATE LAW DEPT 200 EAST RANDOLPH STREET, 8TH FLOOR CHICAGO, IL60601 X President & CEO Signatures /s/ Matthew M. Rice - Matthew M. Rice pursuant to a power of attorney from Gregory C. Case 02/18/2015 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The transactions reported were effected pursuant to a trading plan meeting the requirements of SEC Rule 10b5-1. The reporting person entered into the trading plan in August 2014 for the sole purpose of exercising options otherwise scheduled to expire in March and April 2015 with the sale of shares intended to be limited to only those necessary to cover exercise price and applicable taxes. ( 2 )The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $100.95 to $101.22, inclusive. The reporting person undertakes to provide to Aon plc, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. ( 3 )Class A Ordinary Shares acquired upon the vesting of a restricted share unit award. ( 4 )Class A Ordinary Shares withheld by the issuer for the payment of withholding taxes in connection with the vesting of a restricted share unit award. ( 5 )The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $100.31 to $100.89, inclusive. The reporting person undertakes to provide to Aon plc, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. ( 6 )The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $100.12 to $100.975, inclusive. The reporting person undertakes to provide to Aon plc, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. ( 7 )Vesting occurred in accordance with the terms of the Aon Stock Incentive Plan as follows: one-third of the options vested on each of the second through fourth anniversaries of the date of grant. ( 8 )Stock option granted pursuant to the Aon Stock Incentive Plan. ( 9 )The restricted share unit award converts to Class A Ordinary Shares on a 1-for-1 basis. In accordance with U.K. law, the reporting person agreed to pay the issuer the nominal value of US$0.01 per share issued to the reporting person. ( 10 )The restricted share unit award vests in accordance with the terms of the Aon plc 2011 Incentive Compensation Plan as follows: 33 1/3% of the awards vest on each of the first through third anniversaries of the date of grant.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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