Amanda Bynes as Viola / Sebastian Hastings Channing Tatum as Duke Orsino Laura Ramsey as Olivia Lennox Emily Perkins as Eunice Bates, Olivia 's nerdy, eccentric friend and Duke 's lab partner James Snyder as Malcolm Festes, the school nerd and Sebastian 's (Viola 's) rival Robert Hoffman as Justin Drayton, Viola 's ex-boyfriend and Duke 's rival James Kirk as Sebastian Hastings Alex Breckenridge as Monique Valentine, Sebastian 's superficial girlfriend Brandon Jay McLaren as Toby, one of Duke 's best friends Clifton Murray as Andrew, one of Duke 's best friends Jonathan Sadowski as Paul Antonio, one of Viola 's best friends and hair stylist Amanda Crew as Kia, one of Viola 's best friends Jessica Lucas as Yvonne, one of Viola 's best friends David Cross as Principal Horatio Gold Vinnie Jones as Coach Dinklage Julie Hagerty as Daphne Hastings, the mother of Viola and Sebastian John Pyper - Ferguson as Roger Hastings, the father of Viola and Sebastian Lynda Boyd as Cheryl, the debutante ball 's hostess Robert Torti as Coach Pistonek Mark Acheson as Groundskeeper
who plays duke in she's the man
Channing Tatum