X-Men: First Class is a 2011 superhero film based on the X-Men characters appearing in Marvel Comics. It is the fourth mainline installment in the X-Men film series and the fifth installment overall. It was directed by Matthew Vaughn and produced by Bryan Singer, and stars James McAvoy, Michael Fassbender, Rose Byrne, Jennifer Lawrence, January Jones, Oliver Platt, and Kevin Bacon. At the time of its release, it was intended to be a franchise reboot and contradicted the events of previous films; however, the follow-up film X-Men: Days of Future Past (2014) retconned First Class into a prequel to X-Men (2000). First Class is set primarily in 1962 during the Cuban Missile Crisis, and focuses on the relationship between Charles Xavier and Erik Lehnsherr / Magneto, and the origin of their groups—the X-Men and the Brotherhood of Mutants, respectively, as they deal with the Hellfire Club led by Sebastian Shaw, a mutant supremacist bent on enacting nuclear war.

Matthew Allard de Vere Drummond, known professionally as Matthew Vaughn, is an English filmmaker. He has produced films including Lock, Stock and Two Smoking Barrels (1998) and Snatch (2000), and directed Layer Cake (2004), Stardust (2007), Kick-Ass (2010), X-Men: First Class (2011), and Argylle (2024). Vaughn also co-created the Kingsman comic book series and resulting franchise, directing, producing and co-writing the films Kingsman: The Secret Service (2014), Kingsman: The Golden Circle (2017), and The King's Man (2021).