He played Captain James T. Kirk of Star Trek from 1966 to 1994, and won the Saturn Life Career Award in 1980. During his Star Trek days, he also played eponymous police sergeant T.J. Hooker.
After graduating from McGill University, he worked as a business manager for the Mountain Playhouse in Montreal.
He appeared on Boston Legal and won a People's Choice Award for Favorite New TV Drama series for his reality-based show, Rescue 911.
He married second wife Marcy Lafferty in 1973, and the couple divorced in 1994 after having three children together.
He starred on the hit TV drama Boston Legal alongside Candice Bergen.