Cowboy Bebop: The Movie, known in Japan as Cowboy Bebop: Knockin' on Heaven's Door (Japanese: カウボーイビバップ 天国の扉, Hepburn: Kaubōi Bibappu: Tengoku no Tobira, lit. Cowboy Bebop: Heaven's Door), is a 2001 Japanese anime science fiction action film based on the 1998 anime series Cowboy Bebop created by Hajime Yatate. Several staff from the original series worked on the film, including director Shinichirō Watanabe, writer Keiko Nobumoto, character designer/animation director Toshihiro Kawamoto and composer Yoko Kanno. The Japanese and English voice casts also reprised their roles from the series.

Cowboy Bebop: The Movie is set between episode 22 and episode 23 of the original series. The plot centers on a mysterious terrorist planning to exterminate the human population of Mars by releasing a virus. The bounty hunter crew of the spaceship Bebop works to capture the terrorist and prevent the attack.

The film was conceived by Watanabe as an extension of his work on the television series, which he had treated as a series of miniature films. So as not to alienate existing fans, much of the series' style was retained, with adjustments to make it accessible to a new audience. Increased budget and production facilities enabled filming styles associated with live action films, as well as higher-quality animation than in the series. Arabic aesthetics were used, in contrast to the series, which entailed Watanabe traveling to Morocco for research. Arabic elements also influenced Kanno's music.

The film was produced by studios Sunrise, which had previously developed the original series; Bones, a later studio founded by former Sunrise staff; and Bandai Visual. Cowboy Bebop: The Movie was released to theaters in Japan on September 1, 2001, and in the United States on August 11, 2002. It went on to gross over $3 million worldwide, and when released on DVD, it ranked high on Japanese and US charts. The film received generally positive reviews from mainstream and anime critics, and was nominated for the Online Film Critics Society Award for Best Animated Film.