X0508 4 2024-02-15 0000315293 Aon plc AON 0001322803 Case Gregory C 200 EAST RANDOLPH ST. CHICAGO IL 60601 true true false false Chief Executive Officer false Class A Ordinary Stock 2024-02-15 4 A false 126144 A 427400.841 D Class A Ordinary Stock 2024-02-15 4 F false 56220.593 314.37 D 371180.248 D Class A Ordinary Stock 2024-02-16 4 M false 2356 A 373536.248 D Class A Ordinary Stock 2024-02-16 4 F false 994.672 311.24 D 372541.576 D Class A Ordinary Stock 222985 I By GRAT Class A Ordinary Stock 128052 I By Trust Class A Ordinary Stock 128052 I By Trust Class A Ordinary Stock 145486 I By Trust Class A Ordinary Stock 145485 I By Trust Class A Ordinary Stock 400000 I By GRAT Restricted Share Unit (Right to Receive) 2024-02-16 4 M false 2356 0 D 2026-02-17 Class A Ordinary Shares 2356 4714 D Represents Class A Ordinary Shares issued upon the settlement of performance share unit awards originally granted approximately three years ago under the sixteenth cycle of the Company's Leadership Performance Program. The number of shares issued was determined by the Organization and Compensation Committee of the Board of Directors on February 15, 2024, based on the Company's performance for the period from January 1, 2021 to December 31, 2023. Class A Ordinary Shares withheld by the issuer for payment of taxes in connection with the vesting of the award. Class A Ordinary Shares acquired upon the vesting of a restricted share unit award. The restricted share unit award converts to Class A Ordinary Shares on a 1-for-1 basis. In accordance with Irish law, the reporting person agreed to pay the issuer the nominal value of $0.01 per share issued to the reporting person. A restricted share unit award was granted on February 17, 2023 and vests in accordance with the terms of the Aon plc 2011 Incentive Compensation Plan, as amended and restated: 33 1/3% of the award vests on each of the first through third anniversary of the date of grant. /s/ Colby Alexis - Colby Alexis pursuant to a power of attorney from Greg Case 2024-02-20