For Disney, he played Scott Larson in the 1980 film Midnight Madness. He also provided the voice of Chance in the 1993 film Homeward Bound: The Incredible Journey and its 1996 sequel, as well as voiced Milo Thatch in the 2001 animated feature film Atlantis: The Lost Empire and Michael in the Phineas and Ferb episode "The Curse of Candace". Additionally, he portrayed Michael Chapman in the 1993 Touchstone Pictures film Life with Mikey and Ethan West in the ABC TV show Designated Survivor.
- Fox came up with the fake middle initial "J" because there was already another Michael Fox in the union and he didn't want magazine headlines to read "Michael A. Fox". He said that the J stood for "Jenius".
- Fox was also considered for the role of Chicken Little in the 2005 film of the same name, along with Matthew Broderick and David Spade.
- He was considered for the role of Obi-Wan Kenobi in Star Wars: The Phantom Menace.