Born Michael Andrew Fox in Edmonton, Alberta, Canada, he adopted the "J" as an homage to character actor Michael J. Pollard. Moving several times during the course of his childhood, Michael and his family settled in Burnaby, a suburb of Vancouver. At the age of 15 he made his professional acting debut in the situation comedy Leo and Me.

Moving to Los Angeles at the age of 18, Fox appeared in several small parts and a television series, Palmerstown, U.S.A., before landing the role that would bring him to prominence in Family Ties. Some of his other films include Bright Lights, Big City, The Hard Way, Light of Day, Doc Hollywood and the three "Back to the Future" films.
Revealed in the 7 December 1998 issue of People magazine that he was diagnosed with Parkinson's disease in 1991. Listed as one of twelve "Promising New Actors of 1985" in John Willis' Screen World, Vol. 37. Mother is actress Phyllis Fox. Adopted the "J." as an homage to character actor Michael J. Pollard. Dated Nancy McKeon. Owned a black Ferrari Mondial coupe. [1987] Quit high school before graduating from his senior year. Has said he regrets quitting high school as a "stupid youthful mistake." Has forbidden any of his kids to quit high school for Hollywood, demanding that they at least finish high school and maybe attend 1-2 years of college. According to an interview with Fox, he originally decided to use the middle initial J instead of his own A because he didn't want teen magazines to use headlines such as "Michael, A Fox!". Is a vegetarian. Sister is stage (Shaw Festival) and TV actress Kelli Fox. Was not the first choice to play Alex P. Keaton on Family Ties. He was only chosen after Matthew Broderick, who was originally considered for the role, refused to have a long-term TV obligation. Has written his own book titled "Lucky Man" about Parkinson's and other things he has to deal with in life. When filming Doc Hollywood, he noticed his finger twitching. He was unable to control it. He then saw a doctor and was diagnosed with Parkinson's. Although he never received a real high school diploma, Fox was given an honorary high school diploma from John Dewey High School in Coney Island, Brooklyn, New York, when he spoke at their graduation in 1984. Has a theatre named after him located in his hometown of Burnaby, B.C., Canada. He received his G.E.D. in 1995. Received his first guitar for christmas when he was 8. He taught himself how to play. He was on Planet Hollywood's Wall Of Fame. Received his Hollywood Walk Of Fame Star on December 16th 2002. He is good friends with Boston Bruin's Legend, Cam Neely. He attended the retirement of Neely's number on January 12th, 2004 at the Fleet Center in Boston. NBC President Brandon Tartikoff didn't like initially like Michael because he couldn't see his face looking good on a lunchbox. Ironically, Fox did not allow this type of marketing when the Family Ties became popular. Negotiated the deal for Family Ties from a phone booth outside a now defunct Pioneer Chicken restaurant in Hollywood because he had no phone at home. He was told the network would need to call, and he said he was only home between the hours of four and five. He waited for the call, and fortunately he was there to answer it and secure the Family Ties role. Accidentally injured co-star James Woods's finger on the set of The Hard Way. Woods was throwing him into a popcorn machine when his finger got caught in the button hole of Fox's jacket and dislocated it. While filming Teen Wolf, a location scout was in the same neighborhood, and Michael asked what company he was with. The scout said it was for the new Robert Zemeckis movie called Back to the Future. Michael remarked how it sounded like a good movie and how he hoped someday he'd be part of a film like that. When Eric Stoltz was fired as Marty McFly, on Back to the Future, Fox went on to replace him and the ambition came true. Announced he is leaving Spin City because of Parkinson's disease. [January 2000] He, Jim Carrey and the late Raymond Burr head the list of top Canadians in U.S. television compiled by Banff Television Festival, June 2002. Has four children with Tracy Pollan; Sam Michael (born 1989), twins Aquinnah Kathleen and Schuyler Frances (born 1996) and Esme Annabelle (born 2001). Family Ties creator Gary David Goldberg didn't like Michael after his first audition, stating that he played Alex too smart-alecky. Casting director Judith Weiner fought for him, so Goldberg gave him one more chance. He approached the second audition differently and was later called and offered the part. There is a pub in London, Ontario called "The Alex P. Keaton" in honor of his character on Family Ties. Shares a birthday with Johnny Depp and Natalie Portman. Due to his suffering from Parkinson's Disease, during his run on Spin City, he often hid his right hand in his pocket. Ranked #23 in TV Guide's list of "TV's 25 Greatest Teen Idols" (23 January 2005 issue). His best-known roles, Alex Keaton and Marty McFly, both contain numerous references to Ronald Reagan. Alex Keaton is a conservative Republican whose hero is Ronald Reagan. In Back to the Future, Marty informs an incredulous Doc Brown that Ronald Reagan, the actor, becomes the President of the United States. In Back to the Future Part II, Marty goes into the Cafe 80s, which is "hosted" by a computer-generated video image of President Reagan. In Back to the Future Part III, Michael almost got to work with Reagan himself. By this time Reagan's second term was drawing to a close, if not already over, so director Robert Zemeckis offered him the role of the 1885 mayor of Hill Valley (which may have been in reference to Reagan's first public office, that of Governor of California). Reagan declined. When he was paying his dues as a struggling actor in Hollywood, he sold every last piece of furniture he owned shortly before he landed the role in Family Ties. Went to the same school as Bryan Adams during the 1970s. He donated many items to Rocky Stone to be given to less fortunate kids as part of the Toy Mountain Campaign. His quote "Pain is temporary, film is forever." is from the movie Three o'Clock High.