According to Entertainment Weekly, the actors will both feature as recurring characters on Nip/Tuck creator Ryan Murphy's upcoming show.
Garber has been slated to play the father of main character Will (Matthew Morrison), while Chenowith's part is being kept under wraps.
The series, which has been granted a 13-episode order, focuses on a Spanish teacher who takes over the worst glee club in America.
Glee will debut midseason on Fox.
