Braff would join a cast that stars Olivier Award winner Rachel Weisz, James Franco, Michelle Williams and Mila Kunis.
The prequel to "The Wizard of Oz" is penned by Mitchell Kapner and David Lindsay-Abaire, playwright of the Pulitzer Prize-winning drama Rabbit Hole, and will be directed by Sam Raimi.
Braff would play the role of Frank, the loyal but under-appreciated assistant to Oz (Franco). Williams is set to play Glinda, the Good Witch who teams up with the Wizard to face off against her evil sisters, Theodora (Kunis) and Evanora (Weisz), for the control of the magical land of Oz.
Braff has been seen in the Shakespeare in the Park production of Twelfth Night. The actor has also recently written a play entitled All New People, to be performed at Second Stage Theatre beginning late June.
Weisz received the Olivier Award in 2010 for her performance in the Donmar revival of A Streetcar Named Desire. Franco is known for his work in films such as "Milk," "Howl" and "Spider-Man," and has been mentioned to appear on Broadway in a revival of Tennessee William's Sweet Bird of Youth. A release date for the film has not yet been announced.