Todd Phillips Director Joaquin Phoenix Arthur Fleck Actor Robert De Niro Murray Franklin Actor Zazie Beetz Sophie Dumond Actor Frances Conroy Penny Fleck Actor Brett Cullen Thomas Wayne Actor Shea Whigham Detective Burke Actor Bill Camp Detective Garrity Actor Glenn Fleshler Randall Actor Leigh Gill Gary Actor Josh Pais Hoyt Vaughn Actor Rocco Luna GiGi Dumond Actor Marc Maron Gene Ufland Actor Sondra James Dr. Sally Actor Murphy Guyer Barry O'Donnell Actor Douglas Hodge Alfred Pennyworth Actor Dante Pereira-Olson Bruce Wayne Actor Carrie Louise Putrello Martha Wayne Actor Sharon Washington Social Worker Actor Hannah Gross Young Penny Actor Frank Wood Dr. Stoner Actor Brian Tyree Henry Carl (Arkham Clerk) Actor April Grace Arkham Psychiatrist Actor Tony D. Head WGC Anchorman Actor Scott Silver Screenwriter Richard Baratta Executive Producer Bruce Berman Executive Producer Michael E. Uslan Executive Producer Aaron L. Gilbert Executive Producer Joseph Garner Executive Producer Walter Hamada Executive Producer Bradley Cooper Producer Emma Tillinger Koskoff Producer Lawrence Sher Cinematographer Jeff Groth Film Editing Hildur Guðnadóttir Original Music Mark Friedberg Production Design Laura Ballinger Art Director Kris Moran Set Decoration Mark Bridges Costume Design Shayna Markowitz Casting