John C. Reilly
Dewey Cox
Jenna Fischer
Darlene Madison
Raymond J. Barry
Pa Cox
Kristen Wiig
Edith
Tim Meadows
Sam
Harold Ramis
L'Chai'm
Frankie Muniz
Buddy Holly
Chris Parnell
Theo
Margo Martindale
Ma Cox
Matt Besser
Dave
Nat Faxon
Awards Show Stage Manager
Conner Rayburn
Dewey Age 8
Chip Hormess
Nate Cox
Terrence Beasor
Country Doctor
Honeyboy Edwards
Old Bluesman
Gerry Black
Harmonica Player
Aron Johnson
Teenage Band
Jack Donovan Saperstein
Teenage Band
Taylor Hubert
Teenage Band
Christopher Hurt
Teenage Band
Matt Price
MC (Teacher)
John Maynard
Man at Talent Show
E.J. Callahan
Second Man at Talent Show
Rance Howard
Preacher
Craig Robinson
Bobby Shad
Paul Bates
Nightclub Manager
Patrick Faucette
Bad Men Bass Player
Philip Rosenthal
Mazeltov
Martin Starr
Schmendrick
Oscar Dillon
Audience Guy at Nightclub
Molly C. Quinn
Teen with Pinups
John Ennis
The Big Bopper
Ed Helms
Stage Manager
Jack White
Elvis Presley
Angela Little
Beth Anne
Odette Annable
Reefer Girl
Tyler Nilson
Bert
Deanna Brooks
Hotel Groupie with Dewey
Ian Roberts
Drug Dealer
Steve Bannos
Prison Guard
Willow Geer
Rehab Nurse
David Doty
Rehab Doctor
Jack Kehler
Press Conference Reporter
Gerry Bednob
The Maharishi
David Krumholtz
Schwartzberg
Tim Bagley
Engineer
Jane Lynch
Gail the Television Reporter
Skyler Gisondo
Dewdrop
Kshitij Pendurkar
Dewey Rahim
Simon Helberg
Dreidel L'Chaim
Jacques Slade
Lil' Nutzzak
Danica Rozelle
Music Video Girl
Lurie Poston
Cox Kid
Maggie Mannion
Cox Kid
Jackson Browne
Jackson Browne
Jewel
Jewel
Lyle Lovett
Lyle Lovett
Stacey Scowley
Pierced Eyebrow Girl
Ajla Hodžić
Pierced Lip Girl
Ghostface Killah
Ghostface Killah
Otis Williams
The Temptations
Ron Tyson
The Temptations
Terry Weeks
The Temptations
Joe Herndon
The Temptations
Bruce Williamson
The Temptations
Eddie Vedder
Eddie Vedder
Jack Black
Paul McCartney (uncredited)
Paul Rudd
John Lennon (uncredited)
Justin Long
George Harrison (uncredited)
Jason Schwartzman
Ringo Starr (uncredited)
Patrick J. Adams
The Kid (uncredited)
Clement Blake
Edith's Father (uncredited)
Patrick Duffy
Patrick Duffy (uncredited)
Morgan Fairchild
Morgan Fairchild (uncredited)
Paul Feig
Different DJ (uncredited)
Amber Hay
LSD Vision (uncredited)
John Michael Higgins
Record Producer
Jonah Hill
Older Nate
Neil Ironfield
Dewey's Child (uncredited)
Cheryl Ladd
Cheryl Ladd (uncredited)
Cheryl Tiegs
Cheryl Tiegs (uncredited)
Serria Tawan
70's African American Woman (uncredited)
Rae Sunshine Lee
Concert attendee
Gregg Lee
Concert attendee
Adam Herschman
Jerry Garcia (uncredited)
Debbie Yeh
Asian Woman 70's (uncredited)