 | Margot Robbie als Harleen Quinzel / Harley Quinn |
 | Ewan McGregor als Roman Sionis / Black Mask |
 | Mary Elizabeth Winstead als Helena Bertinelli / Huntress |
 | Jurnee Smollett als Dinah Lance / Black Canary |
 | Rosie Perez als Detective Renee Montoya |
 | Chris Messina als Victor Zsasz |
 | Ella Jay Basco als Cassandra Cain |
 | Ali Wong als Ellen Yee |
 | Matthew Willig als Happy |
 | Dana Lee als Doc |
 | Steven Williams als Patrick Erickson |
 | Robert Catrini als Stefano Galante |
 | Daniel Bernhardt als Sionis' Chauffeur |
 | François Chau als Mr. Keo |
 | Miyuki Matsunaga als Mrs. Keo |
 | Anna Mikami als Miss Keo |
 | Paul Lasa als Franco Bertinelli |
 | Charlene Amoia als Maria Bertinelli |
 | Ella Mika als Young Helena Bertinelli |
 | Derek Wilson als Tim Evans |
 | Bojana Novaković als Erika |
 | Andy Hoff als Erika's Date |
 | Bruno Oliver als Sal |
 | Michael Masini als Officer Dargo |
 | Judy Kain als Bespectacled Secretary |
 | David Bianchi als Henchman |
 | Rj Wayne als Tough Guy |
 | Eddie Alfano als Helena's Bodyguard |
 | Simon Rhee als Cell Guard |
 | Sala Baker als Prisoner |
 | Zack Whyel als Roman's Healer (uncredited) |
 | Ellay Watson als Roller Derby Fan (uncredited) |
 | Karen Teliha als Nun (uncredited) |
 | Nev Smith als Gotham Detective (uncredited) |
 | Greice Santo als Scantily Clad Crystal (uncredited) |
 | Zeus Sagittarius als Roman's Goon (uncredited) |
 | Talon Reid als Roman's Goon (uncredited) |
 | Matthew Parry-Jones als Club Goer (uncredited) |
 | Brian Nuesi als Husband (uncredited) |
 | Adinett Nsabimana als Girl at the Bar (uncredited) |
 | Brandon Garic Notch als Roman's Lift Goon (uncredited) |
 | Anthony Molinari als Mafiosi (uncredited) |
 | Ego Mikitas als Don (uncredited) |
 | Lenora May als Mrs. Marcucci (uncredited) |
 | Jeff Lipary als BBB Gang Member (uncredited) |
 | Brandon Irvin als Roman's Goon (uncredited) |
 | Damon Hoffman als Bodybuilder (uncredited) |
 | William Guirola als Thug (uncredited) |
 | Nico Greetham als Young Goon (uncredited) |
 | Luis Richard Gomez als Harley Super Fan (uncredited) |
 | Shad Gaspard als Lords Leader (uncredited) |
 | Julian Garcia als Roman's Goon (uncredited) |
 | Eddie J. Fernandez als Gauntlet Cop (uncredited) |
 | Mike Ferguson als Lord of the Avenue (uncredited) |
 | Gerald Downey als Judge (uncredited) |
 | Jack Dourakos als Club Goer (uncredited) |
 | Sadyr Diouf als Roman's Goon (uncredited) |
 | Joey Courteau als Club Dancer (uncredited) |
 | Dan Cole als Officer Timm (uncredited) |
 | Lucas Di Medio als Roman's Bodyguard (uncredited) |
 | Jason Catron als Sprang Bridge Soldier (uncredited) |
 | David Anthony Buglione als Joe Bertinelli (uncredited) |
 | Tim Rigby als RR Passenger |
 | Richard King als Mercedes Gang |
 | Oakley Lehman als Mercedes Gang |
 | Eric Michael Cole als Disgruntled Man |
 | Dennis Keiffer als Mercenary |
 | Sam Hargrave als Mercenary |
 | Efka Kvaraciejus als Mercenary |
 | Kofi Yiadom als Mercenary |
 | Bryan Sloyer als Prisoner |
| Christian Womack als Prisoner |
 | Anthony N. als Prisoner |
 | Caleb Spillyards als Prisoner |
 | George Crayton als Prisoner |
 | Terrence Julien als Cell Guard |
 | K.K. Barrett als Dr. Aguilar |
| Christine Engh als Elderly Woman |
 | Shahaub Roudbari als Smarmy Guy |
 | Shawn Balentine als Key Card Cop |
 | Tim Sitarz als Donut Cop |
 | Buddy Sosthand als Coffee Cup Cop |
 | Chris Carnel als Desk Sergeant |
 | Jesse Bush als Patrol Cop |
 | Charles Carpenter als Processing Officer |
 | Jeremy Denzlinger als Desk Sergeant |
 | Keisha Tucker als Roller Derby Girl |
| James Henry Williams Jr. als Ace Chemical Police Officer |
 | Joe Bucaro III als Carlos Rossi |
 | Paloma Esparza Rabinov als Bitchy Teammate |
 | David Ury als Sleazy Breeder |
 | Sara Montez als Shallow Friend #1 |
 | Izabel Pakzad als Shallow Friend #2 |
 | Kc Strubbe als Naïve Teammate |
 | Jacky Shu als Skeptical Teammate |
 | Daniel Cole als Patrol Cop |
 | Qiang Li als Prisoner |
 | Pramod Kumar als Irate Shopkeeper |
| Margot Robbie | Producer |
| Christina Hodson | Screenplay |
| Cathy Yan | Director |
| Sue Kroll | Producer |
| Bryan Unkeless | Producer |
| Geoff Johns | Executive Producer |
| Walter Hamada | Executive Producer |
| Rich Delia | Casting |
| Julia Saeri Lee | Costume Assistant |
| Craig Dollinger | Boom Operator |
| Bryan Mendoza | Utility Sound |
| Steven Morrow | Sound Mixer |
| Kelley Smith-Wait | Executive In Charge Of Production |
| Hans Ritter | Executive Producer |
| Beatrice Cerezo | Key Art Production Assistant |
| Molly Hunter Flick | Art Department Coordinator |
| Matthew Libatique | Director of Photography |
| Rich Romig | Set Designer |
| Amy Lynn Umezu | Storyboard Artist |
| Jonathan Eusebio | Stunt Coordinator |
| Jon Valera | Fight Choreographer |
| Mark Hawker | Special Effects Supervisor |
| Julien Pougnier | Art Direction |
| Kasra Farahani | Supervising Art Director |
| Claudette Barius | Still Photographer |
| Erin Benach | Costume Designer |
| K.K. Barrett | Production Designer |
| Brittany Petros | Location Manager |
| K.K. Barrett | Production Design |
| Daniel Pemberton | Original Music Composer |
| Jay Cassidy | Editor |
| Evan Schiff | Editor |
| David Ayer | Executive Producer |
| Galen Vaisman | Executive Producer |
| Phil Barrie | Sound Effects Editor |
| Paula Fairfield | Sound Designer |
| Brandon Proctor | Sound Re-Recording Mixer |
| Mark DeSimone | ADR Mixer |
| Luke Gibleon | Sound Effects Editor |
| Darren Maynard | Sound Effects Editor |
| Michael W. Mitchell | Sound Effects Editor |
| Katy Wood | Supervising Sound Editor |
| Samira Khan | Visual Effects Coordinator |
| Annemarie Griggs | Visual Effects Producer |
| Kenneth Au | Visual Effects Supervisor |
| Dominic Pacitti | Set Production Assistant |
| Christina Hodson | Co-Producer |
| Donald Sparks | Co-Producer |
| Sara Bartkiewicz | Production Supervisor |
| Alice S. Kim | Production Supervisor |
| Susan McNamara | Unit Production Manager |
| Daniel Paress | Post-Production Manager |
| Nadeem Ashayer | Second Second Assistant Director |
| Dieter Busch | Assistant Director |
| Oliver Mack Calhoun | Second Unit Director |
| Dino Castelli | First Assistant Director |
| Jonathan Eusebio | Second Unit Director |
| Christina Fong | Second Assistant Director |
| Alexander H. Gayner | First Assistant Director |
| Eric Glasser | Second Assistant Director |
| Matt McKinnon | Second Second Assistant Director |
| Jayson Merrill | First Assistant Director |
| R. Ben Parker | Second Second Assistant Director |
| Matthew D. Smith | Second Unit |
| Donald Sparks | First Assistant Director |
| Chad Stahelski | Second Unit Director |
| Jody Blose | Script Supervisor |
| Kathy McHugh | Script Supervisor |
| Tracy L. Moody | Script Supervisor |
| Paul Dini | Characters |
| Bruce Timm | Characters |
| Brit DeLillo | First Assistant Editor |
| Jared Hasselbach | VFX Artist |
| Jordan Ferrer | Art Direction |
| Gustaf Aspegren | Art Direction |
| Florencia Martin | Set Decoration |
| Cary Ayers | Makeup Artist |
| Deborah La Mia Denaver | Makeup Department Head |
| Lindsay Garrison | Makeup Artist |
| John Maldonado | Makeup Artist |
| Michelle Miller | Makeup Artist |
| Nicole Sortillon Amos | Makeup Artist |
| Cale Thomas | Makeup Artist |
| Samantha Ward | Makeup Artist |
| Kevin Wasner | Makeup Artist |
| Sabrina Wilson | Makeup Artist |
| Christopher Casey | Set Dresser |
| Katie Childs | Set Decoration Buyer |
| Jeremy Cisneros | Set Dresser |
| Scott Edward Collins | Set Dresser |
| Luis G. Hoyos | Set Designer |
| Allison Isenberg | Set Decoration Buyer |
| Erin E. Riegel | Assistant Art Director |
| Michael Thurman | Set Dresser |
| Willard Overstreet | Foley Editor |
| Alan Robert Murray | Supervising Sound Editor |
| Adam Kopald | Sound Effects Editor |
| Onnalee Blank | Sound Re-Recording Mixer |
| Shudhdodhan Milind Ambhore | VFX Artist |
| Austin Baerg | VFX Artist |
| Pierre Bonnette | VFX Artist |
| Marguerite Chantal | VFX Artist |
| Martyn Culpitt | VFX Artist |
| Matthew Dravitzki | Visual Effects Producer |
| Matt Hallen | VFX Artist |
| Mark LeDoux | Visual Effects Supervisor |
| Sagar Lonkar | VFX Artist |
| Joaquin Ludewig | VFX Artist |
| Yael Majors | Visual Effects Supervisor |
| Jesse Morrow | Visual Effects Producer |
| Julie Osborn | Visual Effects Producer |
| Michael Perdew | Visual Effects Producer |
| Adam Pere | Visual Effects Producer |
| Hunter Rosenberg | VFX Artist |
| Jaymes Ruffin | VFX Artist |
| Brendan Seals | Visual Effects Supervisor |
| Thrain Shadbolt | Visual Effects Supervisor |
| Cathy Shaw | VFX Artist |
| Kevin Souls | Visual Effects Supervisor |
| Doug Spilatro | VFX Artist |
| Georgina Street | Visual Effects Producer |
| Anthony Almaraz | Set Costumer |
| Corey Bronson | Set Costumer |
| Kelly Porter (costumer) | Set Costumer |
| James Logan | Stunts |
| Michael Bauman | Gaffer |
| Kay Hoddy | Rotoscoping Artist |
| Megan Gray | Assistant Costume Designer |
| Gary Archer | Prosthetics |
| Aviel Ayoung | Stunts |
| Rocky Abou-Sakher | Stunts |
| Can Aydin | Stunts |
| Dean Bailey | Stunt Driver |
| Shawn Balentine | Stunts |
| Matt Berberi | Stunts |
| Eric Brown | Stunts |
| Nick Benseman | Stunts |
| Joe Bucaro III | Stunts |
| Heather Bonomo | Stunts |
| Tony Carbajal | Stunts |
| David Anthony Buglione | Stunts |
| Lee Chesley | Stunts |
| Tim Connolly | Stunts |
| Anis Cheurfa | Stunts |
| Rockey Dickey Jr. | Stunt Coordinator |
| Bruce Concepcion | Stunts |
| Brandon Cornell | Stunts |
| Alyma Dorsey | Stunts |
| Cory DeMeyers | Stunts |
| Eddie J. Fernandez | Stunts |
| Guy Fernandez | Stunts |
| Josh Fried | Stunts |
| Jeremy Fry | Stunts |
| Jeremy Fitzgerald | Stunts |
| Shad Gaspard | Stunts |
| Marilyn Giacomazzi | Stunts |
| Anisha Gibbs | Stunts |
| Tad Griffith | Stunts |
| Daniel Graham | Stunts |
| Akihiro Haga | Stunts |
| Yoko Hamamura | Stunts |
| Craig Henningsen | Stunts |
| John Hennigan | Stunts |
| Ben Jenkin | Stunts |
| Kirk A. Jenkins | Stunts |
| Micah Karns | Stunts |
| Jocelyn Kay | Stunts |
| Dennis Keiffer | Stunts |
| Marissa Labog | Stunt Double |
| Efka Kvaraciejus | Utility Stunts |
| Keone Kim | Stunts |
| Dave Lovano | Stunts |
| Bethany Levy | Stunt Driver |
| Tara Macken | Stunts |
| Adam Lytle | Stunts |
| Monica Lopez Aleman | Stunts |
| Hiroo Minami | Stunts |
| Jeremy Marinas | Stunts |
| Mark Miscione | Stunts |
| Renae Moneymaker | Stunt Double |
| Anthony Molinari | Stunts |
| Tristen Morts | Stunts |
| James Moontasri | Stunts |
| Blake Moya | Stunts |
| Robert Nagle | Stunt Driver |
| Lachlan Robbie | Stunts |
| Scott Rogers | Stunt Coordinator |
| Tim Rigby | Stunts |
| Jade Quon | Stunts |
| Simon Rhee | Stunts |
| Chris Palermo | Stunts |
| Sydney Olson | Utility Stunts |
| Mike Mukatis | Stunts |
| Anthony N. | Stunts |
| Chris Reid | Stunts |
| Steve Rizzo | Stunt Driver |
| Amanda Ruth Ritchie | Stunts |
| Eddie Perez | Stunt Driver |
| Spencer Sano | Stunt Driver |
| Ross Scharphorn | Stunts |
| Zhanna Sattsaeva | Stunts |
| Cale Schultz | Stunts |
| Bryan Sloyer | Stunts |
| Brett Sheerin | Stunts |
| Jackson Spidell | Stunts |
| Dena Sodano | Stunt Driver |
| Caleb Spillyards | Stunts |
| Daniel Stevens | Stunts |
| Keisha Tucker | Stunts |
| Yavuz Topuz | Stunts |
| Mark Aaron Wagner | Stunts |
| Sonja Wajih | Stunts |
| Kyro Wavebourne | Stunt Driver |
| Willie Weber | Stunt Driver |
| Aaron V. Williamson | Stunts |
| Kyle Weishaar | Stunts |
| Vaia Zaganas | Stunt Double |
| Hayley Wright | Stunt Double |
| Duy Pham | Visual Effects |
| Takayuki Sato | Title Graphics |
| Chuck Dixon | Thanks |
| Jolene Van Vugt | Stunt Double |
