Waterworld is a 1995 American post-apocalyptic action film directed by Kevin Reynolds and co-written by Peter Rader and David Twohy. It was based on Rader's original 1986 screenplay and stars Kevin Costner, who also produced it with Charles Gordon and John Davis. It was distributed by Universal Pictures.

The setting of the film is in the distant future. The polar ice caps have completely melted, and the sea level has risen over 7,600 m (25,000 ft), covering nearly all of the land. The plot of the film centers on a nameless antihero, "The Mariner", a drifter who sails the Earth in his trimaran.

The most expensive film ever made at the time, Waterworld was released to mixed reviews from critics, who praised the futuristic setting and premise, but criticized the execution, including the characterization and acting performances. The film also was unable to recoup its massive budget at the box office despite being the ninth highest-grossing film of 1995; however, the film did later become profitable owing to video and other post-cinema sales. The film was nominated for an Academy Award in the category Best Sound at the 68th Academy Awards.

The film's release was accompanied by a novelization, video games, and four themed attractions at Universal Studios Hollywood, Universal Studios Singapore, Universal Studios Japan, and Universal Studios Beijing called WaterWorld, all of which are still running as of 2024.