Back to the Future Part II is a 1989 American science fiction comedy film and the second installment of the Back to the Future trilogy. It was directed by Robert Zemeckis, written by Zemeckis and Bob Gale, and starred Michael J. Fox, Christopher Lloyd, Thomas F. Wilson and Lea Thompson. Part II and the third installment of the trilogy, Back to the Future Part III, were filmed back-to-back, with some of the scenes of Part II and Part III filmed concurrently, and released six months apart. Although released in 1989 and 1990, both films continued to portray 1985 as the present, due to them directly following the events of the first film.

Continuing where Back to the Future left off, Marty McFly and Dr. Emmett "Doc" Brown use the DeLorean time machine to travel to 2015. While there, Biff Tannen steals the DeLorean to travel back to give his teenage self a sports almanac, creating an alternative, dystopian 1985. McFly and Doc are forced to travel to 1955 to repair the timeline. The film has a cliffhanger ending that is resolved in Part III. Back to the Future Part II was released in the United States on November 22, 1989. The film was a commercial success, earning $331.95 million at the international box office, which (unadjusted) at the time was the 12th highest grossing film worldwide, and it received mixed to positive reviews from film critics.