Stults was interested in acting and wrestling in high school. He got his career start in life as a model. A commercial agent spotted Stults eating lunch one day and stopped to give him her card and he then entered into the world of acting. At the time, Stults seriously considered joining the U.S. Navy. George auditioned for a role on 7th Heaven where his younger brother Geoff already had a recurring role as Mary Camden's love interest Ben Kinkirk. Originally auditioning for the role of a kid who forces people to drink, George was later cast in the role of Ben's older brother Kevin. Stults remained a regular cast member of 7th Heaven from season 6 until the final season 11.
In 2001, George made a guest appearance on a season 7 episode of Friends, The One With Joey's New Brain as Jessica Lockhart's daughter's boyfriend.