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

Director

Jake Kasdan