Company: FORFF
Filing Date: 2025-08-01
Form Type: 6-K
Source: 0001666175-25-000044
Chunk: 0

Company: Fortis Inc.
Filing Date: 2025-08-01
Form: 6-K
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549
<div align='center'>FORM 6-K</div>

### REPORT OF FOREIGN PRIVATE ISSUER

#### PURSUANT TO RULE 13a-16 OR 15d-16

#### OF THE SECURITIES EXCHANGE ACT OF 1934

#### For the month of August, 2025
<div align='center'>Commission File Number: 001-37915</div>

#### Fortis Inc.

#### Fortis Place, Suite 1100

#### 5 Springdale Street

#### St. John's, Newfoundland and Labrador

#### Canada, A1E 0E4
<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 40F: Form 20-F o Form 40-F þ

<div align='center'>EXHIBITS</div>

### 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.

| Date: August 1, 2025 |     | Fortis Inc.       
 (Registrant)      
 /s/ James R. Reid |     |                                                                  |
|:---------------------|:----|:------------------|:----|:-----------------------------------------------------------------|
|                      |     | By:               |     | James R. Reid                                                    |
|                      |     | Title:            |     | Executive Vice President, Sustainability and Chief Legal Officer |