Company: FORFF
Filing Date: 2025-06-16
Form Type: S-8 POS
Source: 0001104659-25-059694
Chunk: 0

Company: Fortis Inc.
Filing Date: 2025-06-16
Form: S-8 POS
Chunk 0
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<div align='center'>As filed with the Securities and Exchange Commission on June 16, 2025</div>

Registration No. 333-226663

<div align='center'>UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

POST-EFFECTIVE

AMENDMENT NO. 3

FORM S-8

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

FORTIS INC.

(Exact name of registrant as specified
in its charter)</div>

| Newfoundland and Labrador,               
 Canada                                   
 (State or                                
 other jurisdiction of                    
 incorporation or organization)           | 98-0352146          
 (I.R.S. Employer    
 Identification No.) |
| Fortis Place, Suite 1100                 
 5                                        
 Springdale Street                        
 St. John’s, Newfoundland and             
 Labrador                                 
 Canada                                   
 (709) 737-2800                           
 (Address of Principal Executive Offices) | A1E 0E4             
 (Zip Code)          |

<div align='center'>Tucson Electric Power Company 401(k) Plan

(Full title of plan)

FortisUS Inc.

c/o The Corporation Trust Company
Corporation Trust Center

1209 Orange Street

Wilmington, DE 19801

(302) 658-7581</div>

(Name, address and telephone
number, including area code, of agent for service) with copies to:

<div align='center'>James R. Reid

Executive Vice President, Sustainability and Chief Legal Officer

Fortis Inc.

Fortis Place, Suite 1100

5 Springdale Street

St. John’s, Newfoundland and Labrador, Canada

A1E 0E4

(709) 737-2800</div>

Indicate by check mark whether
the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging
growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting
company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

| Large accelerated filer x | Accelerated filer ¨       |
| Non-accelerated filer ¨   | Smaller                   
 reporting company ¨       |
|                           | Emerging growth company ¨ |

If an emerging growth company,
indicate by check mark if