Adam Sandler Producer, Michael Newman
Kate Beckinsale Donna Newman
Christopher Walken Morty
Jennifer Coolidge Janine
Sean Astin Bill
Katie Cassidy Samantha at 27 years old
Jonah Hill Ben at 17 years old
Henry Winkler Ted
Cameron Monaghan Kevin O'Doyle
James Earl Jones Narrator of Michael's Past (voice) (uncredited)
Terry Crews Singing Driver (uncredited)
Rob Schneider Prince Habeeboo (uncredited)
Julie Kavner Trudy
David Hasselhoff Ammer
Jorge Garcia Ammer in SAP scene (uncredited)
Nick Swardson Bed, Bath & Beyond Guy
Rachel Dratch Alice / Alan
Blake Clark Roy (uncredited)
Jana Kramer Julie
Rick Baker Special Effects Makeup Artist
Carolyn Hennesy Kathy O'Doyle
Toshi Toda Watsuhita Executive
Tim Herlihy Executive Producer, Doctor
Brian Ruberg Foley Mixer
Billy Slaughter Newman Employee (uncredited)
J.J. Perry Stunts
Frank Coraci Director, Male Nurse
Jake Hoffman Ben at 22-30 years old
Tatum McCann Samantha at 5 years old
Lorraine Nicholson Samantha at 14 years old
Gary A. Hecker Foley Artist
Roger Wall Second Assistant "B" Camera
Neal H. Moritz Producer
Bill Corso Prosthetic Makeup Artist
Sophie Monk Stacy
Vanessa Motta Stunts
Lily Mo Sheen Lakeside Camp Girl
Kazu Hiro Prosthetic Supervisor
Jenae Altschwager Judy
Elliott Cho Ping Woo
Steve Koren Producer, Writer
Joseph Castanon Ben at 7 years old
Michelle Lombardo Linda
Marco Khan Habeeboo Entourage
Mark O'Keefe Producer, Writer
Eiji Inoue Watsuhita Executive
Blake Neely Conductor
Rupert Gregson-Williams Original Music Composer
Perry Andelin Blake Production Design
Eric Ramsey Storyboard Artist
Paul Eliopoulos Stunt Coordinator, Stunt Double
Jeffrey J. Haboush Sound Mixer
Roger Mussenden Casting
Dolores O'Riordan Singer
Max Daniels Stunts
Marcei A. Brubaker Brown Second Assistant Director
Katheryn Cain Kirsten
Michael Yama Watsuhita Head Executive
Craig Riley Jr. Best Boy Grip
Clinton Wayne Prosthetic Makeup Artist
Morgan Davis Foehl Assistant Editor
J. Mark Donaldson Stunts
Jack Giarraputo Producer
David V. Butler Dialogue Editor
Spencer Kayden Bar Patron (uncredited)
Michael J. Broomberg Foley Artist
John C. Hartigan Special Effects Coordinator
Tony Rivetti Sr. First Assistant "A" Camera
Dean Semler Director of Photography
Michael T. Ryan Music Editor
Hugo Santiago Set Designer
Vasilios Tanis Makeup Artist