Tommy Chong was in a sitcom.
That '70s Show is an American television period sitcom that originally aired on Fox from August 23 , 1998 , to May 18 , 2006 . The main adult cast members were Debra Jo Rupp , Kurtwood Smith , Don Stark , Tommy Chong and Tanya Roberts . 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 .