Jack Black as Dewey Finn

Joan Cusack as Rosalie Mullins

Mike White as Ned Schneebly

Sarah Silverman as Patty Di Marco

Miranda Cosgrove as Summer Hathaway

Joey Gaydos Jr. as Zack

Kevin Alexander Clark as Freddy Jones

Rivkah Reyes as Katie

Robert Tsai as Lawrence

Maryam Hassan as Tomika

Aleisha Allen as Alicia

Caitlin Hale as Marta

Brian Falduto as Billy

Z Infante as Gordon

James Hosey as Marco

Angelo Massagli as Frankie

Cole Hawkins as Leonard

Lee Wilkof as Mr. Green

Kate McGregor-Stewart as Mrs. Lemmons

Adam Pascal as Theo

Lucas Babin as Spider

Lucas Papaelias as Neil

Chris Stack as Doug

Suzzanne Douglas as Tomika's Mother

Jordan-Claire Green as Michelle

Veronica Afflerbach as Eleni

Jaclyn Neidenthal as Emily

Eron Otcasek as Musician

Carlos Velazquez as Musician

Kimberly Grigsby as Mrs. Sheinkopf

Wally Dunn as Gym Teacher

Tim Hopper as Zack's Father

Michael Dominguez-Rudolph as Art Student

Crash Cortez as Max

Nicky Katt as Razor

John Highsmith as Tony

Heather Goldenhersh as Sheila

Timothy "Speed" Levitch as Waiter

Scott Graham as Punk Rock Guy

Sharon Washington as Alicia's Mother

Kim Brockington as Leonard's Mother

Marty Murphy as Concerned Father

Kathleen McNenny as Freddy's Mother

Joanna Adler as Summer's Mother

Robert Lin as Lawrence's Father

Barry Shurchin as Cop

MacIntyre Dixon as Bus Driver

Amy Sedaris as Mrs. Haynish

Mary Fortune as Teacher's Assistant

Mandy Siegfried as Female Employee

Elle Key as Concert Goer

Carlos J. Da Silva as Security Guard

Ian O'Malley as Radio Exec

Chris Line as Radio DJ

Kyle Meaney as Toby

Frank Whaley as Battle of the Bands Director (uncredited)

Lauren Adler as Concert Goer (uncredited)

Kelly Anne Burns as Groupie (uncredited)

Leanne Cabrera as Concert Goer (uncredited)

Catherine A. Callahan as Concert Goer (uncredited)

Cedric Cannon as Leonard's Dad (uncredited)

Jane DeNoble as Billy's Mom (uncredited)

Caileigh Scott as Concert Goer (uncredited)

Riley G. Matthews, Jr. as Blood Brothers MC Biker (uncredited)

Ryan O'Connor as No Vaccancy's Biggest Fan (uncredited)

Scott Ross as Concert Goer (uncredited)

Johnny Sullivan as Guy in Crowd Who Catches Dewey (uncredited)

Jamie Vergan as Concert Goer (uncredited)

Joe Wachowski as Concert Goer (uncredited)