Alexander Skarsgård as Charles Xavier / Professor X: The telepathic mutant leader and founder of the X-Men. He is a close friend of Erik Lehnsherr until their differing views of mutantkind's place in humanity create a schism between them. Skarsgård was originally auditioned for Erik Lehnsherr however the producers told Skarsgård that he's more suitable for playing Charles.
Jake Gyllenhaal as Erik Lehnsherr / Magneto: A mutant capable of manipulating and generating electromagnetic fields who later befriends with Charles and fights Sebastian together.
Justin Hartley as Henry "Hank" McCoy / Beast: A genius scientist who has mutant abilities similar to those of the great apes. He attempts to cure himself of what he believes to be physically debilitating aspects of his mutation only to be transformed into a frightening-looking blue-furred apeman with leonine attributes. Despite his new appearance, he is kind and caring at heart.
Ben Mendelsohn as Sebastian Shaw: A former mutant Nazi scientist and the leader of the Hellfire Club, a secret society bent on taking over the world. A mutant who has the power of absorbing and redirecting kinetic and radiated energy. He is a former Nazi scientist who killed Erik's parents and the leader of the Hellfire Club, a secret society bent on taking over the world.
Leven Rambin as Emma Frost / White Queen: An extremely strong mutant telepath who can also change her entire body into hard diamond form which grants her superhuman strength, stamina, psionic immunity, and durability, at the cost of using her telepathic abilities. She is a member of the Hellfire Club. Natalie Dormer was originally chosen to play the role since she auditioned for both roles but the producers felt Rambin is more suitable to match Emma's vibe and appearance.
Austin Butler as Alexander "Alex" Summers: A mutant who has the ability to absorb energy and discharge it as blasts and was a student at the Xavier's School for Gifted Youngsters.
George MacKay as Sean Cassidy / Banshee: A mutant capable of emitting incredibly strong ultrasonic screams, sonic blasts, sonic bursts, and sonic waves used in various ways including as a means of flight and was a student at the Xavier's School for Gifted Youngsters. In preparation for the role, MacKay grew his hair much longer than its usual length to match Banshee's appearance in the comics.
Will Peltz as Azazel: A mutant who has the ability to teleport and is also a member of the Hellfire Club.
Ryan Guzman as Roberto "Robert" Da Costa / Sunspot: A mutant with an ability to project solar energy, create flames and solar-powered strength and flight and is also a member of the Hellfire Club. To prepare for the role, Guzman researched Sunspot because when he was cast, he did not know the level of involvement his character has in the film.
