Jim Henry is the youngest of six children, born one and a half hours after his twin brother John. His father, Milburn, was an Air Force test pilot and was stationed all over Europe. His mother, Priscilla, was an Army nurse. Jim's oldest brother and sister, Patrick and Priscilla, are also twins. Jim lost a sister, Cecilia, in an automobile accident in 1985. His other sister, Carol, has always supported him in all of his stunt endeavors, as has the entire family, which is very close. Jim attended the University of Arizona, where he played lacrosse more than he studied. In 1979 he got a taste of Hollywood by being an action extra in the hit Stir Crazy (1980), directed by Sidney Poitier, with Richard Pryor and Gene Wilder. He met one of the biggest names in the stunt world, Mickey Gilbert, who let Jim know it would be a long hard road, but very rewarding in the end.