Joaquin Phoenix (Arthur Fleck / Joker), Robert De Niro (Murray Franklin), Zazie Beetz (Sophie Dumond), Frances Conroy (Penny Fleck), Brett Cullen (Thomas Wayne), Shea Whigham (Detective Burke), Bill Camp (Detective Garrity) more..., Glenn Fleshler (Randall), Leigh Gill (Gary), Josh Pais (Hoyt Vaughn), Rocco Luna (GiGi Dumond), Marc Maron (Gene Ufland), Sondra James (Dr. Sally), Murphy Guyer (Barry O'Donnell), Douglas Hodge (Alfred Pennyworth), Dante Pereira-Olson (Bruce Wayne), Carrie Louise Putrello (Martha Wayne), Sharon Washington (Social Worker), Hannah Gross (Young Penny), Frank Wood (Dr. Stoner), Brian Tyree Henry (Carl (Arkham Clerk)), April Grace (Arkham Psychiatrist), Mick Szal (Woman on Subway), Carl Lundstedt (Wall Street Three), Michael Benz (Wall Street Three), Ben Warheit (Wall Street Three), Gary Gulman (Comedian), Sam Morril (Open Mic Comic), Chris Redd (Comedy Club Emcee), Mandela Bellamy (Mother on Bus), Demetrius Dotson II (Boy on Bus), Greer Barnes (Haha's Clown), Ray Iannicelli (Haha's Clown), Bryan Callen (Haha's Stripper), Peter Hans Benson (Good Morning Host), Vito Gerbino (Street Kid), Adam Quezada (Street Kid), Xavyer Ureña (Street Kid), Evan Rosado (Street Kid), Damian Emmanuel (Street Kid) and others.

Todd Phillips (Producer), Bradley Cooper (Producer), Emma Tillinger Koskoff (Producer), Todd Phillips (Writer), Scott Silver (Writer), Jeff Groth (Editor), Lawrence Sher (Director of Photography) more..., Hildur Guðnadóttir (Original Music Composer), Richard Baratta (Executive Producer), Joseph Garner (Executive Producer), Shayna Markowitz (Casting), Mark Bridges (Costume Design), Mark Friedberg (Production Design), Timothy Metzger (Leadman), Bruce Berman (Executive Producer), Aaron L. Gilbert (Executive Producer), Walter Hamada (Executive Producer), Michael Uslan (Executive Producer), David Webb (Co-Producer), Lawrence Sher (Cinematography), Laura Ballinger (Supervising Art Director), Nicki Ledermann (Makeup Department Head), Kay Georgiou (Hair Department Head), Kris Moran (Set Decoration), G. A. Aguilar (Stunt Coordinator), Airon Armstrong (Stunt Double), Frank Alfano (Stunts), Brian Adler (Visual Effects), Bob Kane (Characters), Bill Finger (Characters), Jerry Robinson (Characters), Tod A. Maitland (Sound Mixer), Randall Poster (Music Supervisor), David Webb (First Assistant Director), Geoffrey Haley (Steadicam Operator), Geoffrey Haley ("A" Camera Operator), Carla Raij (Unit Production Manager), Peter Epstein (Stunts), George Drakoulias (Music Supervisor), Jason Cloth (Co-Executive Producer) and others.