 | Jason Lee als Shoeshine / Underdog (voice) |
 | Jim Belushi als Dan Unger |
 | Patrick Warburton als Cad |
 | John Slattery als Mayor |
 | Peter Dinklage als Dr. Simon Barsinister |
 | Brad Garrett als Riff Raff (voice) |
 | Taylor Momsen als Molly |
 | Amy Adams als Polly Purebred (voice) |
 | Alex Neuberger als Jack Unger |
 | Larry Vigus als Security Guard |
 | Bates Wilder als Cop |
 | Frank Ridley als Police Sergeant |
 | Alexander 'Alex' Garde als Small Boy |
 | Diana Shneider als Police Secretary |
 | Samantha Bee als Principal |
 | John Franchi als Observer |
 | Ezra Buzzington als Referee |
 | Jay Leno als Jay Leno |
 | Susie Castillo als Diana Flores |
 | Phil Morris als Supershep 1 (voice) |
 | Michael Massee als Supershep 2 (voice) |
 | Cam Clarke als Little Brown Dog / Supershep 3 (voice) |
 | John DiMaggio als Bulldog / Supershep 4 (voice) |
 | Danny Mastrogiorgio als Crazy Dog (voice) |
 | Jess Harnell als Astronaut (voice) |
 | Susan Garfield als Office Worker |
| Roger Birnbaum | Producer |
| Gary Barber | Producer |
| Todd Arnow | Executive Producer |
| Todd Arnow | Unit Production Manager |
| Randy Edelman | Original Music Composer |
| Jay Polstein | Producer |
| James F. Truesdale | Art Direction |
| Jonathan Glickman | Producer |
| David Eggby | Director of Photography |
| Adam Rifkin | Screenplay |
| Adam Rifkin | Novel |
| Adam Rifkin | Story |
| Frederik Du Chau | Director |
| Tom Finan | Editor |
| Erin Stam | Co-Producer |
| Joe Piscatella | Screenplay |
| Joe Piscatella | Story |
| Craig A. Williams | Screenplay |
| Craig A. Williams | Story |
| Rebekah Rudd | Co-Producer |
| Philip A. Patterson | First Assistant Director |
| Gail Goldberg | Casting Director |
| Hoyt Yeatman | Visual Effects Supervisor |
| Garreth Stover | Production Design |
| Jon H. Epstein | Stunt Coordinator |
| Bob Brown | Stunt Coordinator |
| Bob Brown | Second Unit Director |
| Gary Jones | Costume Design |
| Eric Ellenbogen | Executive Producer |
| Maggie Martin | Set Decoration |
| Aaron Vexler | Stunts |
| Peggy Nicholson | Hair Department Head |
| Bob Higgins | Executive Producer |
| Paul J. Lombardi | Special Effects Coordinator |
| Tanya Noel Hill | Music Editor |
| Kelly Cronin | Script Supervisor |
| Ben Shepherd | Visual Effects Supervisor |
| Gayle Busby | Visual Effects Producer |
| Andy Fowler | Visual Effects Producer |
| Donna E. Bloom | Unit Production Manager |
| Mark Dornfeld | Visual Effects Supervisor |
| Robert L. Sephton | Sound Designer |
| Robert L. Sephton | Supervising Sound Editor |
| Charles Martin Inouye | Supervising Music Editor |
| Jimmy P. Wong | Stunts |
| Ian Mclaughlin | Stunts |
| Joe Rossi | Makeup Department Head |
| Caroline Vexler | Stunts |
| Boone Narr | Animal Coordinator |
| Shawn Kautz | Stunts |
| Stuart F. Wilson | Stunts |
| Rob Duncan | Visual Effects Supervisor |
| Montez A. Monroe | Production Coordinator |
| Lisa Shaftel | Scenic Artist |
| Joanne Lamstein | Stunts |
| Kimberly Shannon Murphy | Stunts |
| Ellen M. Hillers | Second Assistant Director |
