Aon

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-07-01 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: Aon plc (AON) CIK: 0000315293 --- Reporting Owner --- Name: Reese Edmund CIK: 0001833903 Role: Officer (Chief Financial Officer) --- Non-Derivative Transactions --- [Transaction #1] Security: Class A Ordinary Stock Date: 2026-07-01 | Code: M (Exercise of derivative) Shares: +3,975 Shares Owned After: 6,099.081 | Ownership: D (Direct) Footnotes: [F1] Class A Ordinary Shares acquired upon the vesting of a restricted share unit award. [F1] Class A Ordinary Shares acquired upon the vesting of a restricted share unit award. [Transaction #2] Security: Class A Ordinary Stock Date: 2026-07-01 | Code: F (Payment of exercise/tax) Shares: -2,198.112 | Price: $343.56 Total Value: $755,183.36 Shares Owned After: 3,900.969 | Ownership: D (Direct) Footnotes: [F2] Class A Ordinary Shares withheld by the issuer for payment of taxes in connection with the vesting of the award. --- Derivative Transactions --- [Transaction #1] Security: Restricted Share Unit (Right to Receive) Date: 2026-07-01 | Code: M (Exercise of derivative) Shares: -3,975 | Price: $0.00 Exercisable: N/A | Expires: 2027-07-01 Shares Owned After: 3,975 | Ownership: D (Direct) Footnotes: [F3] 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. [F4] A restricted share unit award was granted on July 1, 2024 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. [F4] A restricted share unit award was granted on July 1, 2024 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. --- Footnotes (Complete Index) --- F1: Class A Ordinary Shares acquired upon the vesting of a restricted share unit award. F2: Class A Ordinary Shares withheld by the issuer for payment of taxes in connection with the vesting of the award. F3: 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. F4: A restricted share unit award was granted on July 1, 2024 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. --- Signature --- /s/ /s/ Colby Alexis - Colby Alexis pursuant to a power of attorney from Edmund Reese (2026-07-06)