Joaquin Phoenix as Arthur Fleck

Robert De Niro as Murray Franklin

Zazie Beetz as Sophie Dumond

Frances Conroy as Penny Fleck

Brett Cullen as Thomas Wayne

Shea Whigham as Detective Burke

Bill Camp as Detective Garrity

Glenn Fleshler as Randall

Leigh Gill as Gary

Josh Pais as Hoyt Vaughn

Rocco Luna as GiGi Dumond

Marc Maron as Gene Ufland

Sondra James as Dr. Sally

Murphy Guyer as Barry O'Donnell

Douglas Hodge as Alfred Pennyworth

Dante Pereira-Olson as Bruce Wayne

Carrie Louise Putrello as Martha Wayne

Sharon Washington as Social Worker

Hannah Gross as Young Penny

Frank Wood as Dr. Stoner

Brian Tyree Henry as Carl (Arkham Clerk)

April Grace as Arkham Psychiatrist

Mick Szal as Woman on Subway

Carl Lundstedt as Wall Street Three

Michael Benz as Wall Street Three

Ben Warheit as Wall Street Three

Gary Gulman as Comedian

Sam Morril as Open Mic Comic

Chris Redd as Comedy Club Emcee

Mandela Bellamy as Mother on Bus

Demetrius Dotson II as Boy on Bus

Greer Barnes as Haha's Clown

Ray Iannicelli as Haha's Clown

Bryan Callen as Haha's Stripper

Peter Hans Benson as Good Morning Host

Vito Gerbino as Street Kid

Adam Quezada as Street Kid

Xavyer Ureña as Street Kid

Evan Rosado as Street Kid

Damian Emmanuel as Street Kid

Mike Troll as Clown Protestor

Jane Fergus as IBN Anchorwoman

David Gibson as WBC News Anchor

Tony D. Head as WGC Anchorman

Jeff McCarthy as NCB Anchor

Kim Brockington as NCB Co-Anchor

Troy Roberts as NCB News Reporter

Lou Young as ANC News Reporter

Michael-Scott Druckenmiller as Paramedic

Craig Austin as Paramedic

John Cenatiempo as Aftermath Police Officer

Danny Schoch as Aftermath Police Officers

Keith Buterbaugh as Band Leader

James Ciccone as Murray Franklin Band

Rich Campbell as Murray Franklin Band

Roger Squitero as Murray Franklin Band

Steven Elson as Murray Franklin Band

Graham Mabry as Murray Franklin Band

John Alldred as Murray Franklin Band

Alonzo Wright as Murray Franklin Band

Jack Wilkins as Murray Franklin Band

Richard Baratta as Murray Franklin Band

Mary Kate Malat as Murray Franklin Intern

Adrienne Acevedo Lovette as Middle Aged Woman (uncredited)

Justin Theroux as Ethan Chase (uncredited)

Alissa Bourne as Anna (uncredited)

Jamaal Burcher as Hospital Visitor / Mfs Audience (uncredited)

John Cashin as Arkham Patient (uncredited)

Jason John Cicalese as Protester / Rioter (uncredited)

Brendan Patrick Connor as Mr. Slotnick (uncredited)

Blaise Corrigan as Taxi Driver (uncredited)

Dennis Jay Funny as Gotham Citizen (uncredited)

James P. Harkins as Thomas Wayne's Body Guard (uncredited)

Joseph Hernandez as Protester / Rioter (uncredited)

Ben Heyman as Protestor (uncredited)

Graham Maby as Murray Franklin Band (uncredited)

Jesse Schratz as Gotham City Sick Kid (uncredited)

Isabella Ferreira as Flirting Woman on the Bus (uncredited)

Shade Rupe as Bartender

Michael Lepre as Arkham Insane Patient (uncredited)