"Sister Act" is the tenth episode of the fourth season of Disney Channel's That's So Raven and the eighty-eighth episode overall. It aired on July 8, 2006. It was written by Michael Feldman and directed by Marc Warren.
Raven and Sydney enter a beauty pageant to raise money for the Community Center. Things get personal when Muffy and her younger sister, Buffy, also enter the pageant. This causes Raven and Muffy to become too competitive, leading to everyone in the room quarreling—even Chelsea, Eddie, Stanley, Cory, Victor, and the audience. When Raven has a vision of Sydney releasing the rope that holds a giant globe that will fall on Buffy during the fight, she stops everyone from fighting. However, all 4 of the girls are immediately "disqualified for starting a fight".
- Raven-Symoné as Raven Baxter
- Orlando Brown as Eddie Thomas
- Kyle Massey as Cory Baxter
- Anneliese van der Pol as Chelsea Daniels
- Rondell Sheridan as Victor Baxter
- Raven-Symoné played the lead in the Broadway version of Sister Act.
- This is Muffy's last appearance in Thats So Raven.