Mbatha-Raw will play role of Plumette, the feather duster in the Beast's castle.
Mbatha-Raw's screen credits include "Doctor Who," "Jupiter Ascending" and "Beyond the Lights."
Beauty and the Beast is scheduled to be released in 3D March 17, 2017. The film will feature original songs from the 1991 film and its subsequent Broadway adaptation that was written by Alan Menken, Howard Ashman and Tim Rice. Menken and Rice will also write new songs to be featured in the film.
Emma Watson ("Harry Potter") will star as Belle, with "Downton Abbey" star Dan Stevens as the Beast, Luke Evans ("The Hobbit," "Dracula: Untiold") as Gaston and Tony Award-nominated Book of Mormon star Josh Gad as Le Fou. Thompson has joined the cast as Mrs. Potts, while Kline has been revealed to play Belle's father, Maurice. McKellen will play Cosgworth, the fretful clock.
According to Disney, "The beloved tale will be retold for the big screen with a modern live-action lens and the help of transformative CG magic."
Bill Condon, who directed the film adaptation of the musical Dreamgirls and penned the screenplay for the film adaptation of Chicago, will direct the film. Production begins in May at Shepperton Studios in London.
The live-action film will feature a script by Stephen Chbosky. David Hoberman and Todd Lieberman produce.
The 1991 animated film of "Beauty and the Beast" won Academy Awards for Best Music, Original Song and Best Music, Original Score. The 1994 Broadway stage adaptation was nominated for nine Tony Awards, winning for Costume Design (Ann Hould-Ward).