Company: AHL
Filing Date: 2025-07-17
Form Type: 6-K
Source: 0001267395-25-000042
Chunk: 0

Company: ASPEN INSURANCE HOLDINGS LTD
Filing Date: 2025-07-17
Form: 6-K
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549

#### Form 6-K
<div align='center'>REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES</div>

#### EXCHANGE ACT OF 1934
<div align='center'>For the month of July 2025

Commission File Number: 001-31909</div>

### ASPEN INSURANCE HOLDINGS LIMITED
<div align='center'>(Translation of registrant’s name into English)</div>

#### 141 Front Street

#### Hamilton HM 19

#### Bermuda
<div align='center'>(Address of principal executive office)</div>

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 ¨

On July 17, 2025, Aspen Insurance Holdings Limited (“Aspen” or the “Company”) issued a press release announcing the appointment of John Welch as Group Chief Underwriting Officer of the Company, effective August 1, 2025.

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

The information included in this Form 6-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

### EXHIBIT INDEX

#### Exhibit
99.1 Press Release dated July 17, 2025

### 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.

| Dated: July 17, 2025 |     | ASPEN INSURANCE HOLDINGS LIMITED 
 By:                              |     | /s/ Mark Pickering      |
|:---------------------|:----|:---------------------------------|:----|:------------------------|
|                      |     | Name:                            |     | Mark Pickering          |
|                      |     | Title:                           |     | Chief