Jennifer Lawrence as Mystique, the shape-shifting mutant.
Michael Fassbender as Magneto, the character originally played by Ian McKellen, who can control metal with his mind.
Ian McKellen plays the elder Magneto after playing the same role in the original "X-Men" trilogy
Hugh Jackman will play Wolverine for the seventh time with "X-Men: Days of Future Past."
Hugh Jackman's Wolverine travels from the future to help change the course of mutant history.
James McAvoy as the psychic Charles Xavier, leader of the X-Men, who later becomes Professor X.
Patrick Stewart returns to the "X-Men" franchise, playing the older Professor X
Peter Dinklage as Bolivar Trask, creator of the mutant fighting robots the Sentinels, in "X-Men: Days of Future Past."
Nicholas Hoult returns as Beast.
Original trilogy cast member Halle Berry as her character Storm, whose power is the ability to control weather
Lucas Till reprises his role as Havok. The character can emit energy beams from his body.
Anna Paquin returns as Rogue in "X-Men: Days of Future Past"
Shawn Ashmore is another one of the original trilogy cast members returning for "Days of Future Past," he plays the mutant Iceman
Ellen Page returns to play Kitty Pryde, who can walk through walls
Evan Peters as Quicksilver in "X-Men: Days of Future Past" is a new addition to the franchise.
Daniel Cudmore reprises his role as Colossus, who has the ability to cover his whole body in an impenetrable metal
Evan Jonigkeit takes over the role of Toad. Ray Parker was the first actor to play the part in 2000's "X-Men."
French actor Omar Sy makes his first foray into blockbuster films with "X-Men" as the mutant Bishop
Josh Helman will play the villainous William Stryker in "X-Men: Days of Future Past."
Fan Bing Bing plays Blink, a new addition to the X-Men team in the future
Booboo Stewart joins the "X-Men" franchise as Warpath
Adan Canto plays Sunspot, another new member of the film's cast.
This is a Sentinel, the mutant-fighting robot that will be featured in the "X-Men" sequel.
Bryan Singer returns to direct "X-Men: Days of Future Past" after directing the first two films in the franchise.