The Cap-Aux-Meules, Que., native beat the reigning Pan Am record holder, Trinidad and Tobago's Njisane Phillip, in the best-of-three-heats final.
Barrette won the first two heats to cruise to Canada's fifth gold in the sport. The 24-year-old took the first heat in 10.409 seconds and the second heat in a time of 10.709.
It was his second gold of the Pan Am Games, as he helped Canada claim the top prize in a thrilling comeback victory in Thursday's men's team sprint final.
The bronze Saturday went to the reigning Pan Am champion, Venezeula's Hersony Canelon Vera.
Track cycling will conclude Sunday with six final races.