Which Ford model was the first Mustang to use the Shelby GT350 name?

The first Mustang to use the Shelby GT350 name was the 1965 Mustang Shelby GT350.

Carroll Shelby transformed selected fastback Mustangs into track-focused performance cars for the 1965 model year. The Shelby GT350 used a modified version of Ford’s 289-cubic-inch V8, suspension changes, weight-saving measures, and distinctive styling. Many examples were prepared for competition, while road versions were sold through Ford-linked channels.

The GT350 established Shelby’s Mustang performance identity before the larger-engined GT500 arrived for 1967. That sequence is a frequent source of confusion because both names became famous, but the GT500 was not the first Shelby Mustang.

Later Shelby Mustangs revived the GT350 name, including modern versions based on the sixth-generation Mustang. The question refers specifically to the original 1965 model.