 | Jason Lee als Dave |
 | David Cross als Ian |
 | Cameron Richardson als Claire |
 | Jane Lynch als Gail |
 | Justin Long als Alvin (voice) |
 | Matthew Gray Gubler als Simon (voice) |
 | Jesse McCartney als Theodore (voice) |
 | Veronica Alicino als Amy |
 | Allison Karman als Female Intern #1 |
 | Tiara Parker als Female Intern #2 |
| Kira Verrastro als Female Intern #3 |
 | Beth Riesgraf als Mother in Store |
 | Adriane Lenox als Vet |
 | Don Tiffany als Engineer |
 | Frank Maharajh als Barry |
 | Kevin Symons als Ted |
 | Jayden Lund als Security Guard |
 | Alexis Boyd als Dancer (as Alexis A. Boyd) |
| Kyndra Reevey als Dancer (as Kyndra 'Binkie' Reevey) |
| Jay Bird als Concert Guest 'Cowboy' |
 | Natalie Cohen als Poolside Girl |
| Kevin Fung als Boy at the Grocery Store |
| Kevin Fisher als Dancer |
 | Jillian Warry Barberie als Herself |
 | Lorne Green als Director |
 | Greg 'G-Spot' Siebel als Photographer |
 | Oliver Muirhead als Butler |
 | Erin Chambers als Press Coordinator |
 | Chris Classic als DJ |
| Adam Riancho als French Doll (voice) |
| Axel Alba als Spanish Doll (voice) |
 | Rosero McCoy als Choreographer |
 | Criscilla Anderson als Dancer |
 | Tucker Barkley als Dancer |
 | Celestina Aladekoba als Dancer |
 | Laura Edwards als Dancer |
 | Christopher Scott als Dancer |
 | Miss Prissy als Dancer |
 | Bryan Gaw als Dancer |
 | Michelle Maniscalco als Dancer |
 | Nick Drago als Dancer |
 | Melanie Lewis als Dancer |
 | Ross Bagdasarian, Jr. als Alvin (singing voice) (uncredited) |
 | Janice Karman als Theodore (singing voice) (uncredited) |
 | Steve Vining als Simon (singing voice) (uncredited) |
| Colette Claire als Bass Player (uncredited) |
 | Sommer Fehmel als Fan (uncredited) |
 | Lisa Mason Lee als Band Member (uncredited) |
 | Rae Sunshine Lee als Concert Attendee (uncredited) |
 | Eddie Mariano als Concert Fan (uncredited) |
 | Meghan Noone als Alvin's Fan (uncredited) |
| Chris Rossi als Dancer (uncredited) |
 | Jameel Saleem als Band Roadie (uncredited) |
| Melanie Stephens als Dancing DJ (uncredited) |
 | Brianna Womick als Girl Hit by Stuffed Chipmunk (uncredited) |
 | Maria Zambrana als Afterparty Patron (uncredited) |
| Gregg Lee als Concert Attendee (uncredited) |
| Doug Jackson | Sound Effects Editor |
| Arnon Milchan | Executive Producer |
| Peter E. Berger | Editor |
| Karen Rosenfelt | Executive Producer |
| Mindy Marin | Casting |
| Toni-Ann Walker | Hair Department Head |
| Anne D. McCulley | Set Decoration |
| Charlie Daboub | Art Direction |
| Jon Vitti | Screenplay |
| Jon Vitti | Story |
| Peter Lyons Collister | Director of Photography |
| Cheri Minns | Makeup Department Head |
| Janice Karman | Producer |
| Tim Hill | Director |
| Will McRobb | Screenplay |
| Chris Viscardi | Screenplay |
| Ross Bagdasarian | Producer |
| Ross Bagdasarian | Characters |
| Michele Imperato | Executive Producer |
| Michele Imperato | Unit Production Manager |
| Steve Waterman | Executive Producer |
| Richard Holland | Production Design |
| Ali Dee | Songs |
| Christopher Lennertz | Original Music Composer |
| Julianne Jordan | Music Supervisor |
| Alexandra Welker | Costume Design |
| R.J. Kizer | ADR Editor |
| David Betancourt | Foley Mixer |
| Scott Curtis | Foley Editor |
| Gloria D'Alessandro | Dialogue Editor |
| Dawn Fintor | Foley Artist |
| David Giammarco | Sound Mixer |
| Tim Gomillion | Sound Recordist |
| Galen Goodpaster | First Assistant Sound Editor |
| Mildred Iatrou | Supervising Sound Editor |
| Paul Massey | Sound Mixer |
| John Murray | Foley Supervisor |
| Dennis Rogers | Sound Recordist |
| Alicia Stevenson | Foley Artist |
| Michele Panelli-Venetis | Associate Producer |
| John Robotham | Stunts |
| Armen Ksajikian | Musician |
| Debbie Evans | Stunts |
| Susan Dawes | Supervising Sound Editor |
| Emily Ferry | Property Master |
| Jaimie Trueblood | Still Photographer |
| Harry Muller | Color Timer |
| Todd Shifflett | Visual Effects Supervisor |
| Evelyne Barbier | Set Designer |
| Emily A. Wilson | Art Department Coordinator |
| Rebecca Robertson | Script Supervisor |
| Angelo Libutti | Animation |
| Leigh Shanta | Unit Production Manager |
| Joel Foster | Animation |
| Justin Hammond | Lighting Technician |
| Dan Haring | Lighting Technician |
| Brett Paton | Animation |
| John Moio | Stunt Coordinator |
| Christopher Flick | Foley Editor |
| Ilana Gordon | Set Decorating Coordinator |
| Sharon E. Alshams | Set Designer |
| Shane D. Kelly | Gaffer |
| Michael Axinn | ADR Editor |
| David MacMillan | Production Sound Mixer |
| George Fisher | Stunts |
| Perry Dodgson | Boom Operator |
| Gary Burritt | Negative Cutter |
| Robert E. Knight | Set Painter |
| Lissette Schettini | Assistant Art Director |
| George Atamian | Set Dresser |
| Craig T. Shordon | Set Painter |
| Kevin E. Patterson | Utility Sound |
| Peggy Teague | Makeup Artist |
| Tom Brown | Music Arranger |
| Christian Wood | Digital Compositor |
