X-Men: First Class is a 2011 American superhero film directed by Matthew Vaughn. It is based on the characters appearing in Marvel Comics and is the fifth installment of the X-Men film series, a prequel to the other films in the franchise. X-Men: First Class was released on June 1, 2011 in the U.K. and on June 3 in the United States.

The film is set primarily in 1962 during the Cuban Missile Crisis and focuses on the relationship between Professor X and Magneto and the origin of their groups, the X-Men and the Brotherhood of Mutants. The film stars James McAvoy as Professor X and Michael Fassbender as Magneto. Other cast members include Kevin Bacon, January Jones, Rose Byrne, Jennifer Lawrence, Zoë Kravitz, Nicholas Hoult and Lucas Till. The film was mostly shot in England and parts of the United States.

At a German concentration camp in occupied Poland in 1944, Sebastian Shaw (under the alias Dr. Schmidt) observes young Erik Lensherr bend a metal gate with his mind when the child is separated from his parents. In his office, Schmidt orders Lensherr to similarly move a metal coin on a desk, and kills his mother when he cannot. Lensherr's out-of-control magnetic power manifest, killing two guards and destroying the room, to Shaw's delight. Meanwhile, in a Westchester County, New York, mansion, young telepath Charles Xavier meets a shape-shifter named Raven. Overjoyed to meet someone else "different" like him, he invites her to live with his family.

In 1962, an adult Lensherr has begun tracking down former Nazi officers, hoping to find Shaw and take revenge. Meanwhile, in England, Oxford University graduate Xavier is publishing his thesis on mutation; his foster sister Raven lives with him. In Las Vegas, Nevada, CIA agent Moira MacTaggert follows U.S. Army Colonel Hendry into the Hellfire Club, where she sees Shaw, Emma Frost, and Azazel. After Shaw threatens Hendry, Azazel disappears with the officer; moments later Hendry is in the War Room, advocating that the U.S. install nuclear missiles in Turkey. Shaw later kills Hendry, revealing the energy-absorbing mutant power that makes him virtually immortal.

MacTaggert, seeking Xavier's advice on mutation, introduces him and Raven to the CIA, where they convince her chief that mutants exist and Shaw is a threat. Though the chief refuses to employ the mutants, they are sponsored by the "Man in Black", another CIA executive. Xavier tracks Shaw down, and arrives in time to stop Lensherr from killing himself in an attempt to stop the escaping Shaw. Xavier brings Lensherr to the CIA's secret "Division X" CIA facility, run by the Man in Black. They meet young scientist Hank McCoy, a prehensile-footed mutant with enhanced intelligence whom Xavier inadvertently outs as a mutant. McCoy, developing a bond with Raven, promises her that he will find a way to normalize their appearance. Xavier uses a mutant-locating device, Cerebro, to find and recruit mutants for training to stop Shaw. He and Lensherr find stripper Angel Salvadore; taxi driver Armando Muñoz, who takes the code name Darwin; army prisoner Alex Summers, who calls himself Havok; and Sean Cassidy, who dubs himself Banshee. Raven eventually takes the name Mystique.

When Frost meets with a Soviet general, Xavier and Lensherr capture her. Meanwhile, Azazel, Riptide and Shaw attack Division X, killing everyone but the young mutants and offering them the chance to join him. Angel accepts, and when Darwin tries to rescue her, Shaw kills him. With the facility destroyed, Xavier takes the mutants to train at his family mansion. McCoy devises protective uniforms and a stealth jet.

President John F. Kennedy institutes a blockade to stop a Soviet freighter from moving nuclear missiles to Cuba. Shaw (wearing a helmet that foils Xaviers telepathic abilities) accompanies the Soviet fleet to ensure the missiles arrive, trying to trigger World War III and mutant ascendency under nuclear holocaust. Raven tries to seduce Lensherr, but he turns down her advances, and convinces her to embrace her nature as a mutant. McCoy soon offers Raven his cure for her appearance, but she refuses. The cure backfires on McCoy, rendering him a leonine beast. Though ashamed of his new appearance, he pilots the mutants and MacTaggert to the blockade line. In an ensuing battle with Shaw, Lensherr takes the helmet for himself, allowing Xavier to immobilize Shaw. Despite Xavier's objections, Lensherr then kills Shaw by forcing the concentration camp coin through his brain.

Fearing the mutants, the fleets fire their missiles at them. In a struggle, Xavier keeps Lensherr from destroying the fleets with the missiles, but when MacTaggert fires at Lensherr, a deflected bullet hits Xavier in the spine. Lensherr, remorseful, leaves with Mystique, Angel, Riptide and Azazel. A wheelchair-bound Xavier and the mutants return to the mansion, where he intends to open a school. MacTaggert promises to never reveal his location and they kiss, when Xavier wipes her memories of the events. Lensherr, now calling himself "Magneto", breaks Frost from confinement.