The Back to the Future trilogy is a comedic science fiction film trilogy written by Bob Gale and Robert Zemeckis, directed by Zemeckis, and distributed by Universal Pictures. The plot follows the adventures of high-school student Marty McFly (Michael J. Fox) and scientist Dr. Emmett Brown (Christopher Lloyd) as they use a modified De Lorean automobile to time travel to different periods in the history of Hill Valley, California.

The first film was the highest grossing film of 1985 and became an international phenomenon, leading to two sequels which were filmed back-to-back and released in 1989 and 1990 respectively. The trilogy is widely noted for its irreverent comedy, eccentric characters and ability to incorporate complex theories of time-travel without confusing the audience. Though the two sequels did not perform quite as well at the box office as the first film, the trilogy remains immensely popular after 20 years and has yielded such spin-offs as an animated television series and a motion-simulation ride at the Universal Studios theme parks in Orlando, Florida (now closed); Universal City, California (closed on September 3, 2007), and Osaka, Japan.