Begun as a line of toys from Hasbro Inc. in 1983, the franchise has expanded massively after the 2010 premiere of an animated TV series featuring talking ponies who are distinguished by colorful flowing manes and unique "cutie marks" on their haunches.
Chenoweth will play a new character who will be introduced for the film. No further details about the role were reported.
Several previous animated "My Little Pony" features were developed for the video market.
The movie with Chenoweth is currently in production by Hasbro and distributor Lionsgate Pictures. Studio CEO Jon Feltheimer was reported saying that the film is designed to generate sequels.