Tommy Chong was in a Fox sitcom.
Leonard `` Leo '' Chingkwake ( Born 1919 ) is a fictional character on the Fox sitcom That '70s Show , portrayed by Tommy Chong . Thomas B. Kin Chong ( born May 24 , 1938 ) is a Canadian-American comedian and actor , who is known for his marijuana-themed Cheech & Chong comedy albums and movies with Cheech Marin , as well as playing the character Leo on Fox 's That '70s Show .