Hailing from Canada, where he grew up the youngest of five children to Bill and Phyllis Fox, Michael struggled in school and was too small - he is five feet, four inches tall - to compete in his favorite activity, ice hockey. He found an outlet in drama class, and in 1976 made his professional debut in the CBS series Leo and Me at age 15 (playing a 10-year-old). After starring in the CBS movie Letters from Frank (also filmed in Canada), Fox dropped out of high school and drove to Los Angeles with his father. There, he found work in the series Palmerstown, U.S.A. before landing the role in Family Ties, where he wooed audiences with his confident charm and impeccable comic timing for seven years.
In 2004, Fox guest starred in the television comedy Scrubs as Dr. Kevin Casey, a surgeon with obsessive-compulsive disorder. In 2006, he appeared in a recurring role on the drama Boston Legal. Fox was nominated for an Emmy Award for best guest appearance. In 2009, he appeared on the dark drama, Rescue Me, and his television special Michael J. Fox: Adventures of an Incurable Optimist, based on his best-selling book by the same title, aired on ABC.
Fox married the actress Tracy Pollan (who played Ellen, Alex Keaton's girlfriend, on Family Ties) in 1988. The couple has four children: son Sam, twin girls Aquinnah and Schuyler, and daughter Esmé Annabelle.