Robert De Niro
Murray Franklin
Joaquin Phoenix
Arthur Fleck
Justin Theroux
Ethan Chase (uncredited)
Shea Whigham
Detective Burke
Zazie Beetz
Sophie Dumond
Gregory Irwin
First Assistant "A" Camera
Brett Cullen
Thomas Wayne
Frances Conroy
Penny Fleck
Bill Camp
Detective Garrity
Isabella Ferreira
Flirting Woman on the Bus (uncredited)
John Cenatiempo
Aftermath Police Officer, Stunts
Bob Kane
Characters
Hannah Gross
Young Penny
Brian Tyree Henry
Carl (Arkham Clerk)
Todd Phillips
Writer, Director, Producer
Douglas Hodge
Alfred Pennyworth
Bill Finger
Characters
Marc Maron
Gene Ufland
George Drakoulias
Music Supervisor
Josh Pais
Hoyt Vaughn
Shannon Nallan
Set Decoration Buyer
Bryan Callen
Haha's Stripper
April Grace
Arkham Psychiatrist
Walter Hamada
Executive Producer
Frank Wood
Dr. Stoner
Sondra James
Dr. Sally
Bruce Berman
Executive Producer
Murphy Guyer
Barry O'Donnell
Airon Armstrong
Stunt Double
Sharon Washington
Social Worker
Mark Bridges
Costume Design
Chris Redd
Comedy Club Emcee
Greer Barnes
Haha's Clown
Mick Szal
Woman on Subway
Adrienne Acevedo Lovette
Middle Aged Woman (uncredited)
Jeff McCarthy
NCB Anchor
Brendan Patrick Connor
Mr. Slotnick (uncredited)
Lawrence Sher
Director of Photography, Cinematography
Dan O'Connell
Foley Artist
Ray Iannicelli
Haha's Clown
G.A. Aguilar
Stunt Coordinator
Blaise Corrigan
Taxi Driver (uncredited)
Hildur Guðnadóttir
Original Music Composer
Jason Cloth
Co-Executive Producer
Kay Georgiou
Hair Department Head
David Gibson
WBC News Anchor
Randall Poster
Music Supervisor
Christian Wenger
Sound Effects Editor
Gary Gulman
Comedian
John T. Cucci
Foley Artist
Laura Ballinger
Supervising Art Director
Mark Friedberg
Production Design
Tony D. Head
WGC Anchorman
Jane Fergus
IBN Anchorwoman