Little Nemo: Adventures in Slumberland (released in Japan as simply Nemo (ニモ, Nimo) and credited in some territories as Little Nemo) is a 1989 animated musical fantasy film directed by Masami Hata and William Hurtz. Based on the comic strip Little Nemo by Winsor McCay, the film went through a lengthy development process with a number of screenwriters. Ultimately, the screenplay was credited to Chris Columbus and Richard Outten; the storyline and art style differed from the original version. The original soundtrack was penned by the Academy Award-winning Sherman Brothers. The film features the English dub voices of Gabriel Damon, Mickey Rooney, René Auberjonois, Danny Mann, and Bernard Erhard.

Even though it derived from an American comic strip, Little Nemo was animated by the Japanese company Tokyo Movie Shinsha and thus is often considered an anime film, although it was a joint production of Japanese and American animators and production companies.

The movie was infamous for being in development hell for much of the 1980s, with many people involved with the production at some point before dropping out. Some of those attached to the film worked at Disney, Lucasfilm, Warner Bros. Animation, and Studio Ghibli. Those who expressed interested or were involved at some stage included George Lucas, Chuck Jones, Ray Bradbury, Isao Takahata, Brad Bird, Jerry Rees, Chris Columbus, Ken Anderson, Frank Thomas, Oliver Johnston, Paul Julian, Osamu Dezaki, the Sherman Brothers (Richard M. Sherman and Robert B. Sherman), Hayao Miyazaki (who was working at TMS at the time), and Gary Kurtz.

The film was first released in Japan on July 15, 1989, by the Toho-Towa and in the United States on August 21, 1992, by the Hemdale Film Corporation for the dub. It received mixed reviews and was a box-office bomb, earning $11.4 million on a $35 million budget. However, it sold well on home video and has since become a cult film.