Report of Foreign Issuer Pursuant to Rule 13a-16 or 15d-16 (6-k)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of October 2021

Commission File Number: 001-31909

ASPEN INSURANCE HOLDINGS LIMITED

(Translation of registrant’s name into English)

141 Front Street

Hamilton HM 19

Bermuda

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ý Form 40-F ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): Yes ¨ No ý

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): Yes ¨ No ý

On October 15, 2021, Aspen Insurance Holdings Limited (“Aspen”) issued a press release announcing that the Group CFO, Kevin Chidwick, has decided to retire and will be leaving Aspen at the end of the year. Kevin will be succeeded by Christopher (Chris) Coleman, who will be taking on the role of Group CFO on October 19th. Chris will be based in Bermuda and will join the Executive Committee.

The press release, furnished as Exhibit 99.1 to this Form 6-K, is incorporated by reference as part of this Form 6-K.

EXHIBIT INDEX

Exhibit

99.1 Press Release dated October 15, 2021.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.