Christopher Walken Morty
Kate Beckinsale Donna Newman
Adam Sandler Producer, Michael Newman
Jennifer Coolidge Janine
Sean Astin Bill
Cameron Monaghan Kevin O'Doyle
Rob Schneider Prince Habeeboo (uncredited)
Katie Cassidy Samantha at 27 years old
Jonah Hill Ben at 17 years old
James Earl Jones Narrator of Michael's Past (voice) (uncredited)
David Hasselhoff Ammer
Jorge Garcia Ammer in SAP scene (uncredited)
Terry Crews Singing Driver (uncredited)
Henry Winkler Ted
Rachel Dratch Alice / Alan
Julie Kavner Trudy
Nick Swardson Bed, Bath & Beyond Guy
Mark O'Keefe Producer, Writer
Tim Herlihy Doctor, Executive Producer
Blake Clark Roy (uncredited)
Gary A. Hecker Foley Artist
Jana Kramer Julie
Lily Mo Sheen Lakeside Camp Girl
Sophie Monk Stacy
Neal H. Moritz Producer
J.J. Perry Stunts
Billy Slaughter Newman Employee (uncredited)
Jake Hoffman Ben at 22-30 years old
Steve Koren Producer, Writer
Marco Khan Habeeboo Entourage
Spencer Kayden Bar Patron (uncredited)
Roger Mussenden Casting
Toshi Toda Watsuhita Executive
Michelle Lombardo Linda
Jack Giarraputo Producer
Carolyn Hennesy Kathy O'Doyle
Jenae Altschwager Judy
Rupert Gregson-Williams Original Music Composer
John Collins Assistant Art Director
Frank Coraci Male Nurse, Director
Michael Yama Watsuhita Head Executive
Clinton Wayne Prosthetic Makeup Artist
Howard London ADR Mixer
Max Daniels Stunts
Ann Pala Makeup Department Head
Bill W. Benton Sound Mixer
Rick Baker Special Effects Makeup Artist
Jim Rygiel Visual Effects Designer
Bill Corso Prosthetic Makeup Artist
Tatum McCann Samantha at 5 years old
Perry Andelin Blake Production Design
Dolores O'Riordan Singer
Blake Neely Conductor
David Elliott Construction Coordinator
Jason Tamez Production Coordinator
Kazu Hiro Prosthetic Supervisor
Barry Bernardi Executive Producer
Clayton Weber Sound Effects Editor
Corina C. Duran-Rabichuk Makeup Artist
Dean Semler Director of Photography
Armen Ksajikian Musician
Cameron Steenhagen Dialogue Editor
David V. Butler Dialogue Editor
Vanessa Motta Stunts
Alan Au Art Direction
John C. Hartigan Special Effects Coordinator
Tony Rivetti Sr. First Assistant "A" Camera
Mark Allen Sound Effects Editor
Joseph Castanon Ben at 7 years old
Kevin Grady Co-Producer
Michael Dilbeck Music Supervisor
Elmo Weber Supervising Sound Editor