From Wikipedia, the free encyclopedia. Tommy Chong (born May 24, 1938) is a Canadian-American comedian, actor and musician who is well-known for his stereotypical portrayals of hippie-era stoners. He is most widely known for his involvement in the marijuana-themed Cheech & Chong comedy movies with Cheech Marin, as well as playing the character Leo on Fox's That '70s Show. Description above from the Wikipedia article Tommy Chong, licensed under CC-BY-SA, full list of contributors on Wikipedia.