The Iron Giant is a 1999 American animated science fiction film produced by Warner Bros. Feature Animation and directed by Brad Bird in his directorial debut. It is loosely based on the 1968 novel The Iron Man by Ted Hughes (which was published in the United States as The Iron Giant), and was written by Tim McCanlies from a story treatment by Bird. The film stars the voices of Jennifer Aniston, Harry Connick Jr., Vin Diesel, James Gammon, Cloris Leachman, John Mahoney, Eli Marienthal, Christopher McDonald, and M. Emmet Walsh. Set during the Cold War in 1957, the film centers on a young boy named Hogarth Hughes, who discovers and befriends a giant alien robot. With the help of a beatnik artist named Dean McCoppin, Hogarth attempts to prevent the U.S. military and Kent Mansley, a paranoid federal agent, from finding and destroying the Giant.

The film's development began in 1994 as a musical with the involvement of the Who's Pete Townshend, though the project took root once Bird signed on as director and hired McCanlies to write the screenplay in 1996. The film was animated using traditional animation, with computer-generated imagery used to animate the Iron Giant and other effects. The understaffed crew of the film completed it with half of the time and budget of other animated features. Michael Kamen composed the film's score, which was performed by the Czech Philharmonic. It was the final film by Warner Bros. Feature Animation to be fully animated and not a live-action/animation hybrid.

The Iron Giant premiered at Mann's Chinese Theater in Los Angeles on July 31, 1999, and was released in the United States on August 6. The film significantly underperformed at the box office, grossing $31.3 million worldwide against a production budget of $50 million, which was attributed to Warner Bros.' lack of marketing and skepticism towards animated film production following the box office failure of Quest for Camelot in the preceding year. Despite this, the film was praised for its story, animation, musical score, characters, the portrayal of the title character and the voice performances of Aniston, Connick, Diesel, Mahoney, Marienthal, and McDonald. The film was nominated for several awards, winning nine Annie Awards out of 15 nominations. Through home video releases and television syndication, the film gathered a cult following and is widely regarded as a modern animated classic, and one of the greatest animated films ever made. In 2015, an extended, remastered version of the film was re-released theatrically, and on home video the following year.