United 93 is a critically acclaimed 2006 docudrama written and directed by Paul Greengrass that chronicles events aboard United Airlines Flight 93, which was hijacked during the September 11, 2001 attacks. The film attempts to recount with as much veracity as possible (there is a disclaimer that some imagination had to be used), in real time, what has come to be known in the United States as an iconic moment of heroism. The film was made with the full cooperation of all the families of those onboard.

The world premiere of United 93 took place on April 26 at the 2006 Tribeca Film Festival in New York City, a festival founded to celebrate New York City as a major filmmaking center and to contribute towards the long-term recovery of lower Manhattan. Several family members of the passengers aboard the flight attended the premiere to show their support.

The film opened nationwide in the United States on April 28. 10% of the gross from the three day opening weekend were promised towards a donation to create a memorial for the victims of Flight 93.

The film is the first Hollywood feature to draw its narrative directly from the September 11 attacks. Passengers were portrayed in the film by mostly professional, if unknown, actors (Tom Burnett, for instance, is played by Christian Clemenson, who has appeared on Veronica Mars). Roles of flight attendants, pilots, and other aircraft personnel were filled by actual airline employees. Some participants in the real-life events play themselves, notably FAA operations manager Ben Sliney. In an interview for in UK magazine Attitude, casting consultant Lee Dennison discussed his decision to cast unknown actors in the film. Dennison also revealed that stand-ins for the hijackers were used until two weeks into filming and the actors playing them were kept separate from everyone else in order to cultivate more on-screen tension.

The dialogue, which was mostly improvised during rehearsals Greengrass held with the cast, was based on face-to-face interviews between actors and families of those they portray. Almost none of the passengers in the film are referred to by their names. Their identities remain anonymous, emphasizing the group effort over any individual heroics (and also portraying the fact that strangers on an airplane would not know one another's names).

Filming took place on a 20 year old reclaimed Boeing 757, formerly operated by MyTravel Airways, at Pinewood Studios near London, England. The location was chosen both for its financial incentives and to shield actors from unwanted public scrutiny they might have received in the US. Action was filmed with handheld cameras, chosen for their versatility on the close-quarters set and to create a sense of realism.

The title was changed from Flight 93 to United 93 in March 2006, to differentiate it from the A&E film Flight 93. Shortly thereafter, the film was given an 'R' rating by the Motion Picture Association of America for "language, and some intense sequences of terror and violence."

The film was released in US cinemas on April 28th, 2006. It opened second in the weekend box office behind RV, but netted a slightly higher per-screen average. It registered a 91% Tomatometer rating (94% "Cream Of The Crop") on Rotten Tomatoes, earning it a "Certified Fresh" title.

The final shot in the film shows only the hands of the passengers struggling with the hijackers for control of the plane. This is a departure from the 9/11 Commission's account of events. The Commission concluded that there was no evidence that the passengers managed to enter the cockpit and that the flight recorder data showed that the hijackers remained at the controls before the plane rolled onto its back, but they must have judged that the passengers were only seconds from breaching the cockpit and overcoming them.

Initial screenings ended with a closing credits line, "America’s war on terror had begun". This was replaced in the release version with, "Dedicated to the memory of all those who lost their lives on September 11, 2001".

NORAD officials have maintained that they would have intercepted and shot down United 93. We are not so sure. We are sure that the nation owes a debt to the passengers of United 93. Their actions saved the lives of countless others, and may have saved either the Capitol or the White House from destruction. — The 9/11 Commission Report

United Airlines Flight 93 was a Boeing 757-222 flight that regularly flew from Newark International Airport (now known as Newark Liberty International Airport) in Newark, New Jersey, to San Francisco International Airport continuing on to Narita International Airport in Tokyo, Japan, on a different aircraft. On September 11, 2001, the aircraft on the flight was one of the four planes hijacked as part of the September 11, 2001 terrorist attacks. It was the only one of the four planes that did not reach its intended target, instead crashing near Shanksville, Pennsylvania, about 150 miles northwest of Washington, D.C.. This was apparently because crew and passengers, alerted through phone calls, attempted to subdue the hijackers. The hijackers are thought to have crashed the plane to keep the crew and passengers from gaining control. It is believed that pilot LeRoy Homer, flight attendants CeeCee Lyles and Sandra Bradshaw and passengers Todd Beamer, Mark Bingham, Tom Burnett, Andrew Garcia, Jeremy Glick, and Richard Guadagno, among others, fought back against the hijackers.

After the trailers for the film began circulating in cinemas, there were calls for Universal Pictures to pull them, due to the upset and surprise caused to some audience members. One theater in Manhattan unilaterally pulled the trailer after audience complaints.

The Iraqi-born, London-based actor Lewis Alsamari, who plays the lead hijacker in the film, was denied a visa by US immigration authorities when he applied to visit New York City to attend the premiere, despite having already been granted asylum in the United Kingdom since the 1990s. The reason given was that he had once been a conscripted member of the Iraqi army - although this was also the grounds for his refugee status after his desertion in 1993.

The official internet forum for the film was shut down as of May 3, 2006, previously available on Universal's website. No word has yet come from Universal as to why the board was removed from their server.

Many Muslims and Muslim American organizations like CAIR worry that United 93 may stir-up more anti-Muslim sentiment in the U.S. In Scottsdale, Arizona on April 29, 2006 three young Muslim women wearing head-covers were verbally attacked by a middle-aged couple who indicated to them that they had watched the movie. After asking the young women if they were Muslim, the couple told them "Take off your fucking burqas and get the fuck out of this country. We don't want you in this country. Go home."

The film has also been criticized for its portrayal of German passenger Christian Adams. Of all passengers on the plane, only Adams is portrayed as counseling appeasement. Sunday Times critic Cosmo Landesman asked "Surely one of the passengers didn't phone home to point out that there was a cowardly German on board who wanted to give in?" Writing in the Guardian (UK), critic John Harris suggested "There will surely be all kinds of cries about old European surrender monkeys [and] the US's contrasting backbone".

In the movie, a short time after takeoff, the pilots make a left turn and note that the passengers on the left side of the plane will be able to see the New York skyline. The passengers look out the left windows, and see the New York skyline, along with a perfect view of the not-yet-damaged World Trade Center. However, according to the official 9/11 Commission, the plane did not take a turn to the left, circling around downtown Manhattan. The plane made an immediate left turn after takeoff, but this would not have allowed the passengers to see New York - they would have seen New Jersey. Assuming the 9/11 Commission's representation of the flightpath is correct, New York City would have been north of the plane all the time while it would have been visible to the passengers - on the right side of the plane, which was travelling west. If any of the passengers had been able to see New York, it would have been the passengers of the right side of the aircraft.

Like the 9/11 Commission Report, the end credits state that the plane crashed at 10:03. However, Cleveland Air Traffic Control reported that Flight 93 went out of radar contact at 10:06 and FAA radar records note a time of 10:06. Seismologists recorded an impact at 10:06:05, give or take a few seconds.