Breanna Clark was born in Los Angelos, California on November 4, 1994. With her mother, Rosalyn Clark, who won a silver medal in the 1976 Summer Olympics, Breanna started competing in track and field at a young age. 

Diagnosed with Autism at age four, she competed at the Paralympic Games, World Championships, and Parapan American Games, helping the United States win the gold medal in the 400m dash each time.