|Marty McFly III|
- "This is Marty's grandson from the timeline where Marty was a corporate flunky not a rock star, but Marty Jr. did not go to jail as a youth."
- —Back to the Future: The Card Game FAQ
Martin Seamus "Marty" McFly III was a possible descendant of Marty McFly and Martin McFly Jr.
Marty McFly III's existence as the third to carry the name of Marty was dependent on the McFly future that Jennifer Parker witnessed in 2015, as deduced by the following events:
- George McFly confronting Biff, kissing Lorraine, and becoming a writer
- Marty McFly getting injured in the car race against Needles
Behind the scenes
- As the card game in which this person appears deals with a series of alternate universes, this character cannot be considered film canon.