In the second episode, "A Family Vacation", Harold McFly (Marty's ancestor in the Middle Ages) and his love, Jennivere, decide to move to Ireland "to raise generations of McFlys". The family stays in Ireland until the 1880s, when Seamus and Maggie McFly move to Hill Valley in "Back to the Future Part III" (1990).
There were plans for a character named Polly Clayton to appear in the series. Polly, aged 9, would presumably have been a relation of Clara's, but the character was dropped before the series aired.
In the episode "A Verne By Any Other Name", Verne tries persuading Jules Verne to change his name to Bart Simpson, so that Doc and Clara will not end up naming him after the author. Dan Castellaneta, the voice of Doc in the series, voices Bart's father Homer in The Simpsons.
The theme song was "Back In Time", which was performed by Huey Lewis and the News at the end of the first film. However, the version used in the series was not sung by the group.
Doc's middle name is revealed to be "Lathrop" in the series. An early draft of "Back to the Future Part III" (1990) had a scene where, in 1885, Doc met a young girl named Sarah Lathrop, who would eventually become his mother.
While, out of the entire cast of all three movies, only Mary Steenburgen (Clara) and Thomas Wilson (Biff) reprise their roles in the *animated* portion of the show, Christopher Lloyd appeared as Doc Brown in live-action bumpers (the parts between the show and the commercials) and in a live-action segment at the end of each episode with Bill Nye, teaching kids about science.