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

Molly Shannon

Stage Actor Joyce

Toby Radloff

Toby Radloff

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

Eli Ganias

Pahls

Sylvia Kauders

Old Jewish Lady

Robert Pulcini

Bob the Director

Mike Rad

Rand

Amy K. Harmon

Cheery Waitress

Jason Stevens

Letterman Regular (voice)