After retiring from boxing in 1932, Callahan refereed hundreds of matches, and he had a 30-year career in Hollywood, taking small roles in movies, most with boxing themes, as well as working as a stuntman, trainer and boxing adviser on movie sets.
Following his retirement from the ring in 1932, Callahan went on to have a distinguished career in Hollywood, landing minor roles in movies that often featured boxing storylines, while also serving as a stunt performer, instructor, and boxing expert on film sets.