From Wikipedia, the free encyclopedia. Michael Robert "Bob" Gale (born May 21, 1951) is an American screenwriter who co-wrote the science fiction film Back to the Future with writing partner Robert Zemeckis, and the screenplays for the film's two sequels. Gale also co-produced all three films. Description above from the Wikipedia article Bob Gale, licensed under CC-BY-SA, full list of contributors on Wikipedia.