Kate Beckinsale Donna Newman
Adam Sandler Producer, Michael Newman
Jennifer Coolidge Janine
Christopher Walken Morty
Jonah Hill Ben at 17 years old
Sean Astin Bill
Cameron Monaghan Kevin O'Doyle
Terry Crews Singing Driver (uncredited)
Henry Winkler Ted
James Earl Jones Narrator of Michael's Past (voice) (uncredited)
Rob Schneider Prince Habeeboo (uncredited)
Nick Swardson Bed, Bath & Beyond Guy
Katie Cassidy Samantha at 27 years old
Rachel Dratch Alice / Alan
Jorge Garcia Ammer in SAP scene (uncredited)
Julie Kavner Trudy
David Hasselhoff Ammer
Kazu Hiro Prosthetic Supervisor
Blake Clark Roy (uncredited)
Billy Slaughter Newman Employee (uncredited)
Rick Baker Special Effects Makeup Artist
Jana Kramer Julie
Steve Koren Producer, Writer
Tim Herlihy Executive Producer, Doctor
Lily Mo Sheen Lakeside Camp Girl
J.J. Perry Stunts
Toshi Toda Watsuhita Executive
Tatum McCann Samantha at 5 years old
Michelle Lombardo Linda
Spencer Kayden Bar Patron (uncredited)
Frank Coraci Director, Male Nurse
Carolyn Hennesy Kathy O'Doyle
Jim Rygiel Visual Effects Designer
Sophie Monk Stacy
Gary A. Hecker Foley Artist
Blake Neely Conductor
Bill Corso Prosthetic Makeup Artist
Marco Khan Habeeboo Entourage
Neal H. Moritz Producer
Michael Yama Watsuhita Head Executive
Perry Andelin Blake Production Design
Melissa Kostenbauder Casting Assistant
Jenae Altschwager Judy
Jake Hoffman Ben at 22-30 years old
Howard London ADR Mixer
Elmo Weber Supervising Sound Editor
Vanessa Motta Stunts
Kevin Grady Co-Producer
Max Daniels Stunts
Roger Mussenden Casting
Eiji Inoue Watsuhita Executive
Alan Au Art Direction
Morgan Davis Foehl Assistant Editor
Jeffrey J. Haboush Sound Mixer
Tammy Sandler Unit Publicist
John Collins Assistant Art Director
Barry Bernardi Executive Producer
Clinton Wayne Prosthetic Makeup Artist
Dolores O'Riordan Singer
Paul Eliopoulos Stunt Coordinator, Stunt Double
Lorraine Nicholson Samantha at 14 years old
Ian Fox "A" Camera Operator
Mark O'Keefe Producer, Writer
Gary Fettis Set Decoration
Jack Giarraputo Producer
Danny McKinnon Max (uncredited)
Rupert Gregson-Williams Original Music Composer
David V. Butler Dialogue Editor
Daryl Kass Unit Production Manager
Rita Smith Production Secretary
David Elliott Construction Coordinator
Joseph Castanon Ben at 7 years old