Michael Keaton

Johnny Dangerously

Joe Piscopo

Vermin

Marilu Henner

Lil

Maureen Stapleton

Mom

Peter Boyle

Dundee

Griffin Dunne

Tommy

Glynnis O'Connor

Sally

Dom DeLuise

The Pope

Richard Dimitri

Maroni

Danny DeVito

Burr

Ron Carey

Pat

Ray Walston

Vendor

Dick Butkus

Arthur

Byron Thames

Young Johnny

Sudie Bond

Cleaning Lady

Alan Hale Jr.

Desk Sergeant

Scott Thomson

Charley

Carl Gottlieb

Dr. Magnus

Neal Israel

Dr. Zillman

Mark Jantzen

Dutch

Hal Riddle

Warden

Mike Bacarella

Vito

Gary Watkins

Manny

Hank Garrett

Mayor

Leonard Termo

Tony Scarano

Troy Slaten

Young Tommy

Alexander Hertzberg

Boy in Suit

Georg Olden

Young Vermin

Cynthia Szigeti

Mrs. Capone

Elizabeth Arlen

Girl on Steps

Doris Grossman

Woman

Richard Warwick

Prisoner

Mike Finneran

Prisoner

Paul B. Brice

Prisoner

Will Seltzer

Prisoner

Dick Balduzzi

Prisoner

Gordon Zimmerman

Prisoner

Katie La Bourdette

Blond Girl

Norman Steinberg

Reporter Duffy

Frank Slaten

Henchman

Dean R. Miller

Photographer

Edward C. Short

Porter

Shelley Pogoda

Woman

Jerome Michaels

Reporter Diering

Russell Forte

Hood

Jack Nance

Priest

Joy Michael

Chorus Girl

Rick Rosenthal

Judge

Paula Dell

Mrs. Zimmer

Harvey Parry

Policeman

Jeffrey Weissman

T-Shirt Vendor

Richard A. Roth

Prisoner Rabbi

Chuck Hicks

Governor

Bob Eubanks

M.C.

Claudia Kim

Girl

Trisha Long

Female Butler

Mert Rich

Man

Vincent Schiavelli

Maroni's Building Planner (uncredited)

Taylor Negron

Delivery Man (uncredited)

Joe Flaherty

Death Row Inmate (uncredited)

Hank Robinson

Policeman (uncredited)

Susan Lanier

Radio Singer (uncredited)

Frank Sivero

Plumber (uncredited)

Tom Willett

Theater Patron (uncredited)