The X-Files (also known as The X-Files: Fight the Future) is a 1998 American science fiction thriller film based on Chris Carter's television series of the same name, which revolves around fictional unsolved cases called the X-Files and the characters solving them. It was directed by Rob Bowman, written by Carter and Frank Spotnitz and featured five main characters from the television series: David Duchovny, Gillian Anderson, Mitch Pileggi, John Neville, and William B. Davis reprise their respective roles as FBI agents Fox Mulder and Dana Scully, FBI Assistant Director Walter Skinner, Well-Manicured Man, and the Cigarette-Smoking Man. The film was promoted with the tagline Fight the Future.

The film takes place between seasons five (episode "The End") and six (episode "The Beginning") of the television series, and is based upon the series' extraterrestrial mythology. The story follows agents Mulder and Scully, removed from their usual jobs on the X-Files, and investigating the bombing of a building and the destruction of criminal evidence. They uncover what appears to be a government conspiracy attempting to hide the truth about an alien colonization of Earth.

Carter decided to make a feature film to explore the show's mythology on a wider scale and appeal to non-fans. He wrote the story with Frank Spotnitz at the end of 1996 and, with a budget from 20th Century Fox, filming began in 1997, following the end of the show's fourth season. Carter assembled cast and crew from the show, as well as some other, well-known actors such as Blythe Danner and Martin Landau, to begin production on what they termed "Project Blackwood". The film was produced by Carter and Daniel Sackheim. Mark Snow continued his role as X-Files composer to create the film's score.

The film premiered on June 19, 1998, in the United States, and received mixed reviews from critics, but was a box office success, earning $189 million worldwide against a budget of $66 million. A sequel, titled I Want to Believe, was released ten years later in 2008.

In 35,000 B.C. during the Ice Age, in what will become North Texas, two cavemen hunters encounter an extraterrestrial life form in a cave, which kills one and infects the other with a black oil-like substance. In 1998, a boy falls into a hole and is also infected by the black oil after it seeps from the ground. Firefighters who enter the hole to rescue him do not come out. A team of men wearing hazmat suits later extract the bodies of the boy and the firefighters. Meanwhile, FBI Special Agents Fox Mulder and Dana Scully, investigating a bomb threat against a federal building in Dallas, discover the bomb in a building across the street. As the building is evacuated, Special Agent in Charge Darius Michaud remains, ostensibly to disarm the bomb. However, he simply waits for the bomb to detonate.

Mulder and Scully are later chastised because, in addition to Michaud, the firefighters and the boy were in the building during the bombing. That evening, Mulder is accosted by paranoid doctor Alvin Kurtzweil, who explains that the "victims" were already dead and that the bombing was staged to cover up how they died. At the hospital morgue, Scully examines one of the victims, finding evidence of an alien virus. Meanwhile, The Smoking Man goes to Texas, where Dr. Ben Bronschweig shows him one of the lost firefighters, who now has an alien organism residing inside his body. The Smoking Man orders Bronschweig to administer a vaccine to it, but to burn the body if it fails. Later, the alien organism gestates and kills Bronschweig.

Mulder and Scully travel to the site of the hole in Texas, finding it has been hastily turned into a new playground, and encountering the boys whose friend fell inside. Driving in the direction indicated by the boys, the pair encounters a train with white gasoline tankers and follow it to a cornfield surrounding two glowing domes. Inside the domes, grates in the floor open and swarms of bees fly out, overwhelming the agents. They flee through an adjacent cornfield, chased by black helicopters, but manage to escape when the helicopters disappear.

In Washington, D.C., Scully attends a performance hearing; meanwhile, Mulder meets with Kurtzweil in an attempt to get more information. Scully arrives at Mulder's apartment to tell him she has been transferred to Salt Lake City. The two are about to kiss when Scully is stung by a bee that had lodged itself under her shirt collar. She falls unconscious while Mulder calls paramedics, but the ambulance driver shoots Mulder and takes Scully away. She is seen later in an isolation unit being loaded onto a plane. An unconscious Mulder is picked up by another ambulance. Not severely injured, he slips out of the hospital with the help of The Lone Gunmen and FBI Assistant Director Walter Skinner. He then meets a former adversary, the Well-Manicured Man, who gives him Scully's location, along with a vaccine against the virus that has infected her. As Mulder leaves, the Well-Manicured Man shoots his driver and then kills himself in a car bomb before his betrayal of The Syndicate is discovered.