Performer(s) Appeared in Martin Seamus "Marty" McFly (Sr.) is one of the main characters from Universal Studios' Back to the Future movie trilogy and related media. Portrayed by Michael J. Fox in the original films, he is an easy-going adolescent who has a part-time job as Dr. Emmett Brown's lab assistant. Marty's only appearance in a Christmas production was, of course, the Back to the Future: The Animated Series episode "Dickens of a Christmas".