Jason Nesmith/Commanter Peter Quincy Taggart

Tim Allen

Gwen DeMarco/Lieutenant Tawny Madison

Sigourney Weaver

Sir Alexander Dane/Dr. Lazarus

Alan Rickman

Fred Kwan/Tech Sergeant Chen

Tony Shalhoub

Guy Fleegman/Security Chief 'Roc' Ingersol

Sam Rockwell

Tommy Webber/Lieutenant Laredo

Daryl Mitchell

Mathesar

Enrico Colantoni

Sarris

Robin Sachs

Quellek

Patrick Breen

Laliari/Jane Doe

Missi Pyle

Teb

Jed Rees

Brandon

Justin Long

Kyle

Jeremy Howard

Katelyn

Kaitlin Cullum

Hollister

Jonathan Feyer

Neru

Sam Lloyd

Lahnk

Rainn Wilson

Tommy Webber/Laredo (age 9)

Corbin Bleu

Excited Alien

J.P. Manoux

Nervous Tech

Dian Bachar

Lieutenant Lathe

Wayne Pere

Fan No. 1

Bill Chott

Fan No. 2

Morgan Rusler

Brandon's Mom

Heidi Swedberg

Announcer (as Kevin Hamilton McDonald)

Kevin McDonald

Fan No. 3

Gregg Binkley

Fan No. 4

Brandon Michael Depaul

Fan No. 5

Paul G. Kubiak

Fan No. 6

Greg Colbrook

Sarris' Guard

Isaac C. Singleton, Jr.

Shy Girl

Jennifer Manley

Teen in the Bathroom No. 1

John Patrick White

Warrior Alien

Joel McKinnon Miller

Sarris' Guard

Isaac C. Singleton

Teen in the Bathroom No. 2

Todd Giebenhain

Reporter

Jerry Penacoli

Navigator

Dan Gunther

Technician No. 1

Matt Winston

Technician No. 2

Brandon Keener

Boy (uncredited)

David Dorfman

Teek

Susan Egan

Sarris' Guard

Issac C. Singleton Jr.

Alien Fan

Daniel T. Parker

Inventory Clerk

Dawn Hutchins

Thermian Greeter No. 1

Lawrence Richards

Thermian Greeter No. 2

Mic Tomasi