Jason Lee as Dave

David Cross as Ian

Jenny Slate as Zoe

Justin Long as Alvin (voice)

Matthew Gray Gubler as Simon (voice)

Jesse McCartney as Theodore (voice)

Amy Poehler as Eleanor (voice)

Anna Faris as Jeanette (voice)

Christina Applegate as Brittany (voice)

Alan Tudyk as Simone (voice)

Michael P. Northey as Hawaiian Shirt Guy

Sophia Aguiar as Club Woman #1

Lauren Gottlieb as Club Woman #2

Tera Perez as Club Woman #3

Andy Buckley as Captain Correlli

Chad Krowchuk as Waiter

Luisa d'Oliveira as Tessa

Tucker Albrizzi as Tucker / Kite Kid

Nelson Wong as Casino Guy

Michael Bagdasarian as Excursion Clerk

Amber-Rochelle DeMarco as Damsel #1

Marcela Caceres as Damsel #2

Natalie Sutcliffe as Damsel #3

Ian Harmon as Monster

Phyllis Smith as Flight Attendant

Ross Bagdasarian, Jr. as Alvin (singing voice) (uncredited)

Janice Karman as Theodore / The Chipettes (singing voice) (uncredited)

Eoin Bates as Music Executive (uncredited)

Seth Robert Dusky as Additional Voices (voice) (uncredited)

Wendell Kinney as Cruise Guest (uncredited)

Jeremy Palko as Cruise Guy (uncredited)

Rachael Wegener as Model (uncredited)