Reese Witherspoon

Character: Susan Murphy / Ginormica (voice)

Seth Rogen

Character: B.O.B. (voice)

Hugh Laurie

Character: Dr. Cockroach Ph.D. (voice)

Rainn Wilson

Character: Gallaxhar (voice)

Will Arnett

Character: The Missing Link (voice)

Kiefer Sutherland

Character: General W.R. Monger (voice)

Paul Rudd

Character: Derek Dietl (voice)

Stephen Colbert

Character: President Hathaway (voice)

Julie White

Character: Wendy Murphy (voice)

Jeffrey Tambor

Character: Carl Murphy (voice)

Amy Poehler

Character: Computer (voice)

Ed Helms

Character: News Reporter (voice)

Renée Zellweger

Character: Katie (voice)

Sean Bishop

Character: Private Bullhorn / Helicopter Pilot / Advisor Ortega (voice)

Rich Dietl

Character: Commander / Advisor Smith (voice)

Rob Letterman

Character: Secret Service Man #1 / Lieutenant (voice)

Tom McGrath

Character: Wilson (voice)

Chris Miller

Character: Advisor Cole / Army Commander Jones (voice)

Mike Mitchell

Character: Advisor Wedgie (voice)

Kent Osborne

Character: Technician Jerry (voice)

Latifa Ouaou

Character: Advisor Ouaou / Mrs. Ronson / Female Advisor #2 / Panicked Guest (voice)

Geoffrey Pomeroy

Character: Soldier #4 / Pilot / Soldier #3 / News Technician (voice)

David P. Smith

Character: Soldier #1 / Advisor Jackson (voice)

Lisa Stewart

Character: Bridesmaid Candy (voice)

Conrad Vernon

Character: Advisor Hawk / Advisor Dither / Minister / Secret Service Man #2 / Mama Dietl (voice)

John Krasinski

Character: Cuthbert (voice)

Stephen Kearin

Character: Technician Bee (voice)