Zachary Levi

Toby

David Cross

Ian

Jason Lee

Dave

Justin Long

Alvin (voice)

Matthew Gray Gubler

Simon (voice)

Jesse McCartney

Theodore (voice)

Amy Poehler

Eleanor (voice)

Anna Faris

Jeanette (voice)

Christina Applegate

Brittany (voice)

Wendie Malick

Dr. Rubin

Anjelah Johnson-Reyes

Julie

Kathryn Joosten

Aunt Jackie

Kevin G. Schmidt

Ryan

Chris Warren

Xander

Bridgit Mendler

Becca

Aimee Carrero

Emily

Alexandra Shipp

Valentina

Gregg Binkley

Emcee

Jake Zyrus

Charice Pempengco

Bernard White

Doctor

Joy Osmanski

Airline Rep

Archie Hahn

Agent

Lanny Joon

Paramedic

Brando Eaton

Jeremy

Michael Bruno

Honor Society

Eric Bauza

Digger the NASCAR Gopher (voice)

Sean Astin

Meerkat Manor Narrator (voice)

Marty Dew

Chipmunk Dancer

Richy Jackson

Chipmunk Dancer

Mihran Kirakosian

Chipmunk Dancer

Thomasina Gross

Chipette Dancer

Rachele Brooke Smith

Chipette Dancer

Ryan Conferido

Li'l Rosero Dancer

Hokuto 'Hok' Konishi

Li'l Rosero Dancer

Ryan Feng

Li'l Rosero Dancer

Steve Terada

Li'l Rosero Dancer

Brittany Anne Pirtle

Cheerleader (uncredited)

Ross Bagdasarian, Jr.

Alvin (singing voice) (uncredited)

Janice Karman

Theodore / The Chipettes (singing voice) (uncredited)

Courtney Platt

Eleanor - Performer (voice) (uncredited)

Gee Alexander

Simon Dance Double (uncredited)

Tallie Brinson

Principal Dancer (uncredited)

David Lautman

High School Student (uncredited)

Casper Smart

Dancer (uncredited)