 | Tim Allen als Jack Sheppard |
 | Courteney Cox als Marsha Holloway |
 | Chevy Chase als Dr. Grant |
 | Spencer Breslin als Tucker Willams / Mega-Boy |
 | Kevin Zegers als Connor Shepard / Concussion |
 | Kate Mara als Summer Jones / Wonder |
 | Michael Cassidy als Dylan West / Houdini |
 | Ryan Whitney Newman als Cindy Collins / Princess |
 | Rip Torn als Larraby |
 | Cornelia Guest als Cindy's Mom |
 | Ashton Moio als Halloween Bully |
 | Hunter Aarniokoski als Prince |
 | Thomas F. Wilson als Dylan's Teacher |
 | Ridge Canipe als Mean Bully |
 | Danny McCarthy als Meaner Bully |
 | David L. Lander als Wendy's Employee |
 | Lauren Sánchez als Reporter |
 | Willie Garson als Dick |
| Jane Hajduk als Researcher Taylor |
| Tommy Chang als Martial Arts Instructor |
 | Zoe Doyle als Researcher |
| Tim Nasiopoulos als Large Agent |
| Deanna DeLisle als Cheerleader |
| Meg Anderson als Cheerleader |
 | Kendra Rose Montagna als Cheerleader |
 | Aaron Abrams als Corporal Lipscombe (uncredited) |
| Stacey Alfano als Stefanie (uncredited) |
 | Nick Baga als Fat Swimmer (uncredited) |
 | Alexis Bledel als Ace (uncredited) |
 | Darryl Dinn als Lab Researcher (uncredited) |
| Allison Gordon als Girl with Big Hair (uncredited) |
| Sadey Paige Nifong als Kid In Pool (uncredited) |
| Andrea Savo als Carmen / Big haired Latina (uncredited) |
| Peter Hewitt | Director |
| Adam Rifkin | Screenplay |
| David Berenbaum | Screenplay |
| Angie Jones | Animation |
| Jason Lethcoe | Novel |
| Adam Rifkin | Screenstory |
| John Papsidera | Casting |
| Lawrence Jordan | Editor |
| Ha Nguyen | Costume Design |
| Virginia Burton | Costume Supervisor |
| Susan Marucci | Script Supervisor |
| Barry Chusid | Production Design |
| Clive Thomasson | Set Decoration |
| Julie Ragland | Co-Producer |
| David Tattersall | Director of Photography |
| Christophe Beck | Original Music Composer |
| Suzanne Todd | Producer |
| Jennifer Todd | Producer |
| Todd Garner | Producer |
| Neil A. Machlis | Executive Producer |
| Nick Osborne | Executive Producer |
| Trevor Engelson | Executive Producer |
| Joseph Boccia | Associate Producer |
| Robert Scherer | Production Sound Mixer |
| Ava Gerlitz | Still Photographer |
| Tim Merkel | Steadicam Operator |
| Joshu de Cartier | Art Direction |
| Tamara Deverell | Art Direction |
| Lisa Shaftel | Property Master |
| Chris Scarabosio | Sound Designer |
| Matthew Wood | Supervising Sound Editor |
| Mark Dornfeld | Visual Effects Supervisor |
| Mark Owen Forker | Visual Effects Supervisor |
| Shelley Cook | Stunt Driver |
| Luci Romberg | Stunts |
| David LeRoy Anderson | Special Effects Makeup Artist |
| Mario Cacioppo | Assistant Makeup Artist |
| Hallie D'Amore | Makeup Artist |
| Christine Hart | Makeup Department Head |
| Carol Hartwick | Assistant Hairstylist |
| Francesca Paris | Hairstylist |
| Ronnie Specter | Makeup Artist |
| Vincent Sullivan | Hair Department Head |
| Toni-Ann Walker | Hairstylist |
| Tim Mogg | Makeup Artist |
| Joseph Boccia | Unit Production Manager |
| Erica Frauman | Post Production Supervisor |
| Robin M. Reelis | Production Supervisor |
| Jeff J.J. Authors | First Assistant Director |
| Simon Board | First Assistant Director |
| Adam Bocknek | Third Assistant Director |
| Chamonix Bosch | Second Second Assistant Director |
| Tyler Delben | Third Assistant Director |
| Eric S. Potechin | Second Assistant Director |
| Peter Aquilina | Scenic Artist |
| Rob Ballantyne | Storyboard Artist |
| Ravi Bansal | Concept Artist |
| David Best | Graphic Designer |
| William Cheng | First Assistant Art Direction |
| Peter Constantinides | Carpenter |
| J.P. Dame | Set Dresser |
| Paul Dolgov | Painter |
| Laura Evans | Set Decoration Buyer |
| David G. Fremlin | First Assistant Art Direction |
| Ryan Galiher | Props |
| Beth Gilinsky | Set Decorating Coordinator |
| Jason Graham | First Assistant Art Direction |
| Adrian Hardy | Set Dresser |
| Kenneth Heimer | Prop Maker |
| Jennifer Heimpel | Assistant Art Director |
| Darryl Henley | Storyboard Artist |
| David Hirschfield | Set Designer |
| Tom Jung | Storyboard Artist |
| Walter Klassen | Special Props |
| Mayumi Konishi-Valentine | Set Designer |
| Glenn Locke | Scenic Artist |
| Meaghan Lynch | Assistant Art Director |
| Jim Magdaleno | Storyboard Artist |
| Rob McCallum | Concept Artist |
| Rob McCallum | Storyboard Artist |
| Kari Measham | Set Decoration Buyer |
| Steve Middlebrook | On Set Dresser |
| Scott Nifong | Property Master |
| Melissa Olson | Props |
| Nick Alachiotis | Stunts |
| Kelly Bellini | Stunts |
| Matt Birman | Stunt Coordinator |
| Hubert Boorder | Stunts |
| Dan Brown | Stunts |
| Brad Bunn | Stunts |
| Randy Butcher | Stunts |
| Tommy Chang | Stunt Coordinator |
| Jeff Chumas | Stunts |
| Larry Holt | Stunts |
| Blair Johannes | Stunts |
| Ciara Jones | Stunt Double |
| Jamie Jones | Stunts |
| Liise Keeling | Stunts |
| Bret Kiene | Stunts |
| Jung-Yul Kim | Stunts |
| Georgia Leva | Stunt Double |
| Scott Leva | Stunts |
| Darren McGuire | Stunts |
| Duncan McLeod | Stunts |
| Ashton Moio | Stunts |
| John Moio | Stunt Coordinator |
| T. Ryan Mooney | Stunts |
| Bonnie Morgan | Stunts |
| Billy Oliver | Stunts |
| Cheryl Quiacos | Stunts |
| Bryan Renfro | Stunts |
| Kevin Rushton | Stunts |
| Kenny Searle | Utility Stunts |
| John Stead | Stunts |
| Booboo Stewart | Utility Stunts |
| Fivel Stewart | Stunt Double |
| Todd Warren | Stunt Double |
| Ron Webber | Stunts |
| Peter Yan | Stunts |
| Bob Yerkes | Stunts |
| Addison Teague | Sound Effects Editor |
