| Haley Joel Osment | David |
| Frances O'Connor | Monica Swinton |
| Sam Robards | Henry Swinton |
| Jake Thomas | Martin Swinton |
| Jude Law | Gigolo Joe |
| William Hurt | Prof. Hobby (the Visionary) |
| Ken Leung | Syatyoo-Sama |
| Clark Gregg | Supernerd |
| Kevin Sussman | Supernerd |
| Tom Gallop | Supernerd |
| Eugene Osment | Supernerd |
| April Grace | Female colleague |
| Matt Winston | Executive |
| Sabrina Grdevich | Secretary |
| Theo Greenly | Todd |
| Jeremy James Kissner | Kid |
| Dillon McEwin | Kid |
| Andy Morrow | Kid |
| Curt Youngberg | Kid |
| Ashley Scott | Gigolo Jane |
| John Prosky | Mr. Williamson (the bellman) |
| Enrico Colantoni | The Murderer |
| Paula Malcomson | Patricia in mirrored room |
| Brendan Gleeson | Lord Johnson-Johnson |
| Michael Berresse | Stage manager |
| Haley King | Amanda |
| Kathryn Morris | Teenage honey |
| Daveigh Chase | Child singer |
| Brian Turk | Backstage bull |
| Justina Machado | Assistant |
| Tim Rigby | Yeoman |
| Lily Knight | Voice in the crowd |
| Vito Carenzo | Big man |
| Rena Owen | Ticket taker |
| Alan Scott | Worker |
| Adam Alexi-Malle | Crowd member |
| Laurence Mason | Tech director |
| Brent Sexton | Russell |
| Ken Palmer | Percussionist |
| Jason Sutter | Percussionist |
| Michael Shamus Wiles | Cop |
| Kelly McCool | Kate (the holographic fgirl) |
| Clara Bellar | FemMecha nanny |
| Keith Campbell | Roadworker |
| Tim Rhoze | Laboratory technician |
| Jim Jansen | Chef |
| Eliza Coleman | Gen. Circuita |
| R. David Smith | Welder |
| Wayne Wilderson | Comedian |
| Bobby Harwell | TV face |
| Billy Scudder | Mechanic |
| Jack Angel | Teddy |
| Robin Williams | Dr. Know |
| Ben Kingsley | Specialist |
| Meryl Streep | Blue Mecha |
| Chris Rock | Comedian |
| Erik Bauersfeld | Gardener |
| Michael Mantell | Dr. Frazier at Cryogenic Institute |
| Miguel Pérez | Robot repairman |
| Matt Malloy | Robot repairman |
| Adrian Grenier | Teen in van |
| Mark Allan Staubach | Teen in van |
| Michael Fishman | Teen in van |
| Jeanine Salla | Sentient Machine therapist |
| Laia Salla | Mr. Chan's assistant |
| Diane Fletcher | Sentient Machine security |
| Kate Nei | Toe Bell Ringing |
| Claude Gilbert | Cybertronics - Room 93056 |
| Red King | Covert Information Retrieval |
| Al Jourgensen | Flesh Fair Band member |
| Paul Barker | Flesh Fair Band member |
| Max Brody | Flesh Fair Band member |
| Duane Buford | Flesh Fair Band member |
| Adam Grossman | Flesh Fair Band member |
| Ty Coon | Flesh Fair Band member |
| Kelly Felix | Butler Mecha |
| John Harmon | Medic Mecha |
| Paul Isaac Martin | Crash test dummy |
| Chris Palermo | Red Biker Hound |
| Claudia Katz | Mecha Robot |
| Katie Lohmann | Pleasure Mecha |
| Sarena Mobley | Exotic girl |
