Form 4 Filing by Richard C. Notebaert

This filing details stock transactions by Richard C. Notebaert, a director at Aon plc. On June 25, 2026, Mr. Notebaert was granted 776 Class A Ordinary Shares, with a nominal value of $0.01 per share, as part of an annual award for non-employee directors. Following this award, he owned 28,513.97 shares. Additionally, on the same date, 186.235 shares were withheld by the issuer for tax payments, resulting in a post-transaction ownership of 28,327.735 shares. The price per share for the withheld shares was $315.95. The filing was signed on June 29, 2026.