Sabrina Carpenter (Cady Heron), Reneé Rapp (Regina George), Krystina Alabado (Gretchen Wieners), Laura Leigh Turner (Karen Smith), Olivia Kaufmann (Janis Sarkisian), Chad Burris (Damian Hubbard), Kyle Selig (Aaron Samuels), Cheech Manohar (Kevin Gnapoor), Catherine Brunell (Mrs. Heron/Ms. Norbury/Mrs. George), Rick Younger (Principal Duvall), Drew Redington (Mr. Heron), Teddy Toye (Coach Carr/Glen Coco/Math Moderator), Stephanie Lynn Bissonnette (Dawn Schweitzer), Collins Conley (Lizzie Therman/Caroline Krafft), Darius Barnes (Christian Wiggins), Pascal Pastrana (Shane Oman), Riza Takahashi (Sophie Kawachi), Devon Hadsell (Caitlyn Caussin), Curtis Holland (Jason Weems), Daryl Tofa (Marwan Jitla), Sasha Hollinger (Rachel Hamilton), Bria Jene Williams (Grace Akinola)