Teenage Mutant Ninja Turtles is a 1990 American live-action film adaptation of the Teenage Mutant Ninja Turtles franchise directed by Steve Barron. The film was followed by three sequels: Teenage Mutant Ninja Turtles II: The Secret of the Ooze in 1991, Teenage Mutant Ninja Turtles III in 1993, and TMNT in 2007. This film presents the origin story of Splinter and the Turtles, the initial meeting between them, April O'Neil and Casey Jones, and their first confrontation with Shredder and his Foot Clan. The film is distributed by New Line Cinema and outside the United States is internationally distributed by Golden Harvest.

When the New York Police Department is unable to stop a severe crime wave caused by the Foot Clan, four vigilantes — Leonardo, Michelangelo, Donatello and Raphael — come forth to save the city. Under the leadership of Splinter and together with their new-found allies April O'Neil and Casey Jones, they fight back and take the battle to Shredder. The film kept very close to the dark feel of the original comics, with several elements also taken from the animated series that was airing at the time, such as April being a news reporter, and the turtles having different-colored masks, as opposed to the uniform red masks of the comic. The film was the highest-grossing independent film of all time when it was released, and became the ninth highest grossing film worldwide of 1990 and the most successful film in the franchise.