Hesseman played the iconic hippie DJ Johnny Fever on the famous sitcom which ran from 1978 to 1982.
Hesseman won two Emmy nods for best-supporting actor for his role on the show.
According to his manager Robbie Kass, Hesseman died from complications of colon surgery.
Hesseman will also be remembered for playing history teacher Charlie Moore on the 80’s comedy Head of the Class!
Before his career in acting, Hesseman worked as a disc jockey at San Francisco rock-and-roll station KMPX and was a member of the San Francisco improv group The Committee.