Form 8-A12B Aon plc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

Form 8-A

FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES

PURSUANT TO SECTION 12(b) OR (g) OF

THE SECURITIES EXCHANGE ACT OF 1934

Aon North America, Inc.

(Exact Name of Registrant as Specified in Its Charter)

Delaware

(State or Other Jurisdiction of Incorporation or Organization)

52-1245792

(I.R.S. Employer Identification no.)

200 East Randolph Street

Chicago, Illinois 60601

United States of America

(Address of Principal Executive Offices) (Zip Code)

Securities to be registered pursuant to Section 12(b) of the Act:

If this form relates to the registration of a class of securities pursuant to Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), check the following box. ☒

If this form relates to the registration of a class of securities pursuant to Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), check the following box. ☐

If this form relates to the registration of a class of securities concurrently with a Regulation A offering, check the following box. ☐

Securities Act registration statement or Regulation A offering statement file number to which this form relates (if applicable):

333-297255,  333-297255-01, 333-297255-02, 333-297255-03 and 333-297255-04

Securities to be registered pursuant to Section 12(g) of the Act:

None.

Item 1. Description of Registrant’s Securities to be Registered.

Aon North America, Inc. (“ANA”) and Aon Global Holdings plc (together with ANA, the “Issuers”) register hereunder their 5.350% Senior Notes due 2029 (the “2029 Notes”), 5.625% Senior Notes due 2031 (the “2031 Notes”), 5.800% Senior Notes due 2033 (the “2033 Notes”), 5.950% Senior Notes due 2036 (the “2036 Notes”), 6.100% Senior Notes due 2038 (the “2038 Notes”), 6.450% Senior Notes due 2046 (the “2046 Notes”) and 6.450% Senior Notes due 2056 (the “2056 Notes” and, together with the 2029 Notes, the 2031 Notes, the 2033 Notes, the 2036 Notes, the 2038 Notes and the 2046 Notes, the “Notes”) and the guarantees thereof (the “Guarantees” and, together with the Notes, the “Securities”) by each of Aon plc, Aon Corporation, and Aon Global Limited (together, the “Guarantors”). The information required by this item in respect of the Securities is incorporated herein by reference to the information set forth under the caption “Description of the Securities” in the Issuers’ Prospectus Supplement, dated September 14, 2026, and under the caption “Description of Debt Securities and Guarantees” in the accompanying Prospectus, dated July 2, 2026, included in the Issuers and the Guarantors’ Registration Statement on Form S-3 (File Nos. 333-297255, 333-297255-01, 333-297255-02, 333-297255-03 and 333-297255-04), filed with the Securities and Exchange Commission (the “Commission”) on September 15, 2026 and July 2, 2026, respectively.

Item 2. Exhibits.

SIGNATURE

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the registrants have duly caused this registration statement to be signed on their behalf by the undersigned, thereto duly authorized.

Dated: September 17, 2026