United 93 is a 2006 film written and directed by British filmmaker Paul Greengrass. The film largely chronicles the events aboard United Airlines Flight 93, one of the four hijacked flights during the September 11 attacks on America. Flight 93 was the only plane to not hit its intended target due to the intervention of passengers and crew. The film also covers the experiences of government officials and air traffic controllers, many of whom are played by themselves, as they witness the other events of the attacks unfold that day.

The film recounts the hijacking and subsequent events during the flight with as much veracity as possible, including utilizing a real time perspective where the film takes place over the exact same amount of time as the real-life events beginning from the plane's takeoff. There is, however, a disclaimer that some imagination had to be used to tell the story. Overall, United 93 was made with the support and cooperation of most of the passengers' families, and many attended the premiere. There were, however, a few who did not support the film and did not participate in any of the film's activities. Many of the on-the-ground personnel, most notably Federal Aviation Administration head Ben Sliney, portray themselves.

United 93 premiered on April 26, 2006, at the Tribeca Film Festival in New York City, and later opened in theaters nationwide in America on April 28, 2006. The film is regarded as one of the best of 2006. It was also a commercial success, grossing $76.3 million worldwide. Ten percent of the gross income from the three-day opening weekend was promised toward a donation to create a memorial for the flight's victims. The film received two Academy Award nominations, including Best Director for Greengrass.