Producer Lauren Shuler Donner first thought of a prequel based on the young X-Men during the production of X2, and later producer Simon Kinberg suggested to 20th Century Fox an adaptation of the comic series X-Men: First Class, though the film does not follow the comic closely. Singer, who had directed both X-Men and X2, became involved with the project in 2009, but he could only produce and co-write First Class due to other projects. Matthew Vaughn, who was previously attached to both X-Men: The Last Stand and Thor, became the director, and also wrote the final script with his writing partner Jane Goldman. First Class overtook a planned Magneto prequel that entered development hell and the Writer's Guild of America arbitration gave a story credit to Magneto writer Sheldon Turner.
First Class entered production in August 2010, with principal photography concluding in December and additional filming finishing in April 2011, just a few weeks before the film's premiere in June 2011. The tight schedule proved a challenge to the six companies responsible for the extensive visual effects, which included computer-generated sets and digital doubles for the actors. Locations included Oxford, the Mojave desert and Georgia, with soundstage work done in both Pinewood Studios and the 20th Century Fox stages in Los Angeles. The depiction of the 1960s drew inspiration from the James Bond films of the period.
First Class was a box-office success, becoming the seventh highest-grossing in the film series, and received positive reviews from critics and audiences, who praised the fresh revival of the franchise as well as its acting, screenplay, direction, action sequences, visual effects, and musical score. A sequel titled X-Men: Days of Future Past was released in May 2014, with Singer returning as director and Vaughn as co-writer. Another sequel, X-Men: Apocalypse, was released on May 27, 2016. A third sequel, Dark Phoenix, is scheduled to be released on February 14, 2019.
In 1944, in a Nazi death camp, Nazi scientist Klaus Schmidt witnesses a young Erik Lehnsherr bend a metal gate with his mind when he is separated from his mother. In his office, Schmidt orders Lehnsherr to move a coin on his desk, and kills the boy's mother when Lehnsherr cannot. In grief and anger, Lehnsherr's magnetic power manifests, killing two guards and destroying the room. Meanwhile, at a mansion in Westchester County, New York, child telepath Charles Xavier meets young shapeshifter Raven, whose natural form is blue-skinned and scaly. Overjoyed to meet someone "different", like himself, he invites her to live with his family as his foster sister.
In 1962, Lehnsherr is tracking down Schmidt, while Xavier graduates from the University of Oxford. In Las Vegas, CIA officer Moira MacTaggert follows U.S. Army Colonel Hendry into the Hellfire Club, where she sees Schmidt — now known as Sebastian Shaw — with mutant telepath Emma Frost, cyclone-producing Riptide, and teleporter Azazel. Threatened by Shaw and teleported by Azazel to the Joint War Room, Hendry advocates deployment of nuclear missiles in Turkey. Shaw, an energy-absorbing mutant whose powers have de-aged him, later kills Hendry.