Paul Giamatti
Harvey Pekar
Hope Davis
Joyce Brabner
Judah Friedlander
Toby Radloff
James Urbaniak
Robert Crumb
Earl Billings
Mr. Boats
James McCaffrey
Fred
Maggie Moore
Alice Quinn
Vivienne Benesch
Lana
Daniel Tay
Young Harvey
Harvey Pekar
Real Harvey
Donal Logue
Stage Actor Harvey
Josh Hutcherson
Robin
Joyce Brabner
Joyce Brabner
Molly Shannon
Stage Actor Joyce
Toby Radloff
Toby Radloff
Eytan Mirsky
Guitarist
Joey Krajcar
Batman
Chris Ambrose
Superman
Cameron Carter
Green Lantern
Mary Faktor
Housewife
Madylin Sweeten
Danielle
Ebon Moss-Bachrach
MTV Director
David Letterman
Self (archive footage)
Kurt Loder
Self (archive footage)
Shari Springer Berman
Interviewer (voice)
Larry John Meyers
Throat Doctor
Barbara Brown
Nurse
Danny Hoch
Marty
Eli Ganias
Pahls
Sylvia Kauders
Old Jewish Lady
Rebecca Borger
Cashier
Nick Baxter
Mattress Guy #1
Allen Branstein
Mattress Guy #2
Dick Prochaska
WWII Patient
Charles Eduardos
Doctor
Robert Pulcini
Bob the Director
Bianca Santos
Counter Girl
Mike Rad
Rand
Amy K. Harmon
Cheery Waitress
Rob Grader
Stage Manager
Terrence Sullivan
Letterman Regular
Patrick Lafferty
Yuppie
Jesse Perez
Miguel
Jeff Peters
Talk Show Host
Ola Creston
PA #1
Robert J. Williams
Cancer Doctor
Jason Stevens
Letterman Regular (voice)
Todd Cummings
Talk Show Host (voice)