Dewey Cox
John C. Reilly
Darlene Madison
Jenna Fischer
Pa Cox
Raymond J. Barry
Edith Cox
Kristen Wiig
Ma Cox
Margo Martindale
Sam
Tim Meadows
L'Chai'm
Harold Ramis
Theo
Chris Parnell
Buddy Holly
Frankie Muniz
Dave
Matt Besser
Nate
Chip Hormess
Young Dewey Cox
Conner Rayburn
Record Producer
John Michael Higgins
Schwartzberg
David Krumholtz
Stage Manager
Nat Faxon
John Lennon
Paul Rudd
Ringo Starr -- uncredited
Jason Schwartzman
Doctor
Terrence Beasor
George Harrison
Justin Long
Harmonica Player
Gerry Black
Elvis Presley
Jack White
Man at Talent Show
John Maynard
Old Bluesman
Honeyboy Edwards
MC--Teacher
Matt Price
Man No.2 at Talent Show
E.J. Callahan
DJ
Jack McBrayer
Dreidel L' Chai'm
Simon Helberg
Preacher
Rance Howard
Teenage Band
Aron Johnson
Bobby Shad
Craig Robinson
Teenage Band
Jack Donovan Saperstein
Nightclub Manager
Paul Bates
Teenage Band
Taylor Hubert
Audience Guy at Nightclub
Oscar Dillon
Teenage Band
Christopher Hurt
Mazeltov
Phil Rosenthal
Schmendrick
Martin Starr
Teenager
Amy Ferguson
Different DJ
Paul Feig
Bad Men Bass Player
Patrick Faucette
Teenage Girl
Molly Quinn
The Big Bopper
John Ennis
Mazeltov
Philip Rosenthal
Stage Manager
Ed Helms
Beth Anne
Angela Little Mackenzie
Reefer Girl
Odette Yustman
Prison Guard
Steve Bannos
Nurse at Rehab
Willow Geer
Doctor at Rehab
David Doty
Reporter No.1
Jack Kehler
Bert
Tyler Nilson
The Maharishi
Gerry Bednob
Engineer No.1
Tim Bagley
Hotel Groupie with Dewey
Deanna Brooks
Drug Dealer
Ian Roberts
Dewdrop
Skyler Gisondo
Dewey Rahim
Kshitij Pendurkar
Lil' Nutzzak
Jacques Slade
Music Video Girl
Danica Rozelle
Himself
Eddie Vedder
Himself
Jackson Browne
Herself
Jewel
Gail the Television Reporter
Jane Lynch
Himself
Ghostface Killah
Himself
Lyle Lovett
Paul McCartney -- uncredited
Jack Black
Cox Kid
Lurie Poston
Cox Kid
Maggie Mannion
Pierced Eyebrow Girl
Stacey Scowley
Pierced Lip Girl
Ajla Hodzic
Older Nate
Jonah Hill
The Temptations
Otis Williams
The Temptations
Ron Tyson
The Temptations
Terry Weeks
The Temptations
Joe Herndon
The Temptations
Bruce Williamson
Pygmy Bushman
Don Abernathy
Concert attendee
Rae Sunshine Lee
Concert attendee
Gregg Lee