Singer, who has made similar casting announcements via Twitter, said on the social media site that he "couldn't be more excited" that Berry had joined the film.
"Hopefully she can improve the weather in Montreal," Singer added, referencing the movie's shooting location.
Other returning cast members to the upcoming X-Men flick include Patrick Stewart, Ian McKellen, Hugh Jackman, Anna Paquin, Shawn Ashmore, and Ellen Page, who starred in the original trilogy, and James McAvoy, Michael Fassbender, Jennifer Lawrence, and Nicholas Hoult from "X-Men: First Class."
Actors Peter Dinklage and Omar Sy were also recently added to the cast, although their roles are currently unknown.
Shooting on the film begins later this year. "X-Men: Days of Future Past" is set for release on July 18, 2014.
[via Twitter h/t CinemaBlend]