 | Margot Robbie als Harleen Quinzel / Harley Quinn |
 | Idris Elba als Robert DuBois / Bloodsport |
 | John Cena als Christopher Smith / Peacemaker |
 | Joel Kinnaman als Colonel Rick Flag |
 | Sylvester Stallone als Nanaue / King Shark (voice) |
 | Viola Davis als Amanda Waller |
 | David Dastmalchian als Abner Krill / Polka-Dot Man |
 | Daniela Melchior als Cleo Cazo / Ratcatcher 2 |
 | Michael Rooker als Brian Durlin / Savant |
 | Jai Courtney als George 'Digger' Harkness / Captain Boomerang |
 | Peter Capaldi als Gaius Grieves / The Thinker |
 | Alice Braga als Sol Soria |
 | Pete Davidson als Richard Hertz / Blackguard |
 | Joaquín Cosío als Mayor General Mateo Suarez |
 | Juan Diego Botto als Presidente General Silvio Luna |
 | Storm Reid als Tyla DuBois |
 | Nathan Fillion als Cory Pitzner / T.D.K. |
 | Taika Waititi als Ratcatcher |
 | Steve Agee als John Economos / On-Set King Shark |
 | Sean Gunn als Weasel / Calendar Man |
 | John Ostrander als Doctor Fitzgibbon |
 | Flula Borg als Gunter Braun / Javelin |
 | Mayling Ng als Mongal |
 | Stephen Blackehart als Briscoe |
 | Tinashe Kajese als Flo Crawley |
 | Jennifer Holland als Emilia Harcourt |
 | Fernando Martinez als Sliced Dome Soldado |
 | Dee Bradley Baker als Sebastian (voice) |
 | Jaws als Sebastian Rat |
| Crisp Ratt als Sebastian Rat |
 | Natalia Safran als Kaleidoscope |
| Jared Leland Gore als Double Down |
 | Rey Hernandez als Teniente |
 | Ray Benitez als Coronel |
 | Reinaldo Faberlle als Large Guerrilla |
| Jonathan Fritschi als Delicious Hot Dog Guerrilla |
 | Josh Ventura als Astronaut |
 | Gerardo Davila als General Vera |
 | Mikaela Hoover als Camila |
 | Lynne Ashe als Polka-Dot Man's Mom |
 | Julio Cesar Ruiz als Milton |
 | J.R. Adduci als Road Block Soldado |
| Curtis Lyons Jr. als Road Block Soldado #3 |
 | Maya Le Clark als Young Cleo |
| Elideusa Gomes Almeida als La Gatita Presents Traditional Corto Maltese Dancer |
| Shanna Kernan als La Gatita Presents Traditional Corto Maltese Dancer |
| Bridget Taylor als La Gatita Presents Traditional Corto Maltese Dancer |
| Monica Rivera als La Gatita Presents Traditional Corto Maltese Dancer |
 | Andrea Andrade als La Gatita Waitress |
 | Giovanni Rodriguez als Texting Torturer |
 | Giovannie Cruz als Isabella |
 | Sergio Carlo als Isabella's Second |
| Edgar Zanabria als Torn-In-Half Soldado |
| Grecia Balboa als Security Dispatcher |
 | Kenneth Trujillo als Bespectacled Soldado |
 | Randy Havens als Star-Crossed Man |
| Michelle Civile als Star-Crossed Woman |
| Gabrielle Manning als Star-Crossed Kid |
 | Michael Aaron Milligan als Star-Crossed Dude |
 | Diany Rodriguez als Star-Crossed Gal |
| Teresita Mans als Star-Crossed Lady |
 | Terence Rosemore als Crew Chief |
 | Lloyd Kaufman als Dancing La Gatita Bar Patron (uncredited) |
 | Pom Klementieff als La Gatita Amable Dancer (uncredited) |
 | Victoria Paige Watkins als Tiff (uncredited) |
| Charles Roven | Producer |
| Walter Hamada | Executive Producer |
| James Gunn | Director |
| Judianna Makovsky | Costume Design |
| Beth Mickle | Production Design |
| Lauren Abiouness | Art Direction |
| Simon Hatt | Co-Producer |
| Lisa K. Sessions | Set Decoration |
| Peter Safran | Producer |
| Lars P. Winther | Co-Producer |
| Henry Braham | Director of Photography |
| Filip Dimitrievski | Visual Effects Supervisor |
| John Murphy | Original Music Composer |
| Richard Suckle | Executive Producer |
| Fred Raskin | Editor |
| Chantal Nong Vo | Executive Producer |
| Nik Korda | Executive Producer |
| Deborah Snyder | Executive Producer |
| David Acord | Sound Designer |
| David Acord | Supervising Sound Editor |
| Christopher Boyes | Sound Re-Recording Mixer |
| Dane Butler | ADR Mixer |
| Will Carroll | ADR Recordist |
| Greg Crawford | ADR Mixer |
| Antonio García Cristóbal | ADR Recordist |
| Justin Doyle | Sound Effects Editor |
| Aidan Dykes | ADR Recordist |
| John Harton | Boom Operator |
| Jeffrey A. Humphreys | Boom Operator |
| Ryan Juggler | Assistant Sound Editor |
| Adam Kopald | Sound Effects Editor |
| Brandon Kotfila | ADR Recordist |
| Carson X. MacDonald | Utility Sound |
| Anna MacKenzie | ADR Supervisor |
| Michael Miller | ADR Mixer |
| Jason Oliver | ADR Mixer |
| Lee Orloff | Sound Mixer |
| James Peterson | Sound Mixer |
| Jamison Rabbe | ADR Mixer |
| Gary Rizzo | Sound Re-Recording Mixer |
| Shelley Roden | Foley Artist |
| Brit DeLillo | Assistant Editor |
| Ellen Arden | Makeup Artist |
| Jillian Erickson | Makeup Artist |
| Forrest Hill | Makeup Artist |
| Magdalena Puibusqué | Makeup Artist |
| Leo Satkovich | Makeup Artist |
| Heba Thorisdottir | Makeup Department Head |
| LuAndra Whitehurst | Makeup Artist |
| Alessandro Cioffi | Visual Effects Supervisor |
| Mark Gee | Visual Effects Supervisor |
| Kelvin McIlwain | Visual Effects Supervisor |
| Guy Williams | Visual Effects Supervisor |
| Lorin Flemming | Art Direction |
| Brittany Hites | Art Direction |
| Alan Hook | Supervising Art Director |
| Darshankumar Joshi | Art Direction |
| Alex McCarroll | Art Direction |
| Drew Monahan | Art Direction |
| María Fernanda Muñoz | Art Direction |
| Jay Pelissier | Art Direction |
| Domenic Silvestri | Art Direction |
| Charles Arnold | Grip |
| Jeff Bettis | Grip |
| Dan Cornwall | Gaffer |
| Justin Yard | Grip |
| Blade Ladish | Set Dresser |
| Michael Corrigan | Set Dresser |
| A.J. Austin | Set Dresser |
| Vincent Bates | Set Designer |
| Shane Baxley | Concept Artist |
| Nick S. Cross | Set Designer |
| Matthew R. Cunningham | Concept Artist |
| Robert Fechtman | Set Designer |
| Zachary Fannin | Graphic Designer |
| Marshall T. Broyles | Special Effects Technician |
| Bailey Eller | Special Effects Technician |
| Allison Gainza | Special Effects Technician |
| Ryan Hartnett | Special Effects Technician |
| Keith Haynes | Special Effects Technician |
| Michaela Holgate | Special Effects Technician |
| Todd Jensen | Special Effects Technician |
| Edward Malys | Special Effects |
| Darin O'Neill | Special Effects Technician |
| Shawn Windisch | Special Effects Technician |
| Dexter Bell | Stunts |
| Kelly Bellini | Stunts |
| Paul Burke | Stunts |
| Christopher M. Campos | Stunts |
| Jwaundace Candece | Stunts |
| John Casino | Stunts |
| Travis Fienhage | Stunt Driver |
| James Gunn | Writer |
| Destin Jacobus | Electrician |
| Joshua D. Quick | Electrician |
| Bolivar Aparicio | Prosthetic Makeup Artist |
| Michelle Diamantides | Key Hair Stylist |
| Kristen Saia | Hairstylist |
| John Tarro | Hairstylist |
| Daphne De Jesus | Digital Compositor |
| Matteo Veglia | Line Producer |
| Luke McDonnell | Thanks |
| David Ayer | Thanks |
| John Ostrander | Thanks |
| Laura Baker | Set Costumer |
| Jason Blackman | Set Costumer |
| Kevin Boyett | Set Costumer |
| Jordan Johnson | Set Costumer |
| Ginger Knussmann | Set Costumer |
| Robin McMullan | Costume Supervisor |
| Chris Tonick | Additional Editor |
| Arianne Benedetti | Line Producer |
| Christian Wagner | Editor |
| John Papsidera | Casting |
| Kay Hoddy | Rotoscoping Artist |
| Satoshi Takazawa | VFX Artist |
| Tim Sale | Thanks |
| Coleen M. Tracy | Stunts |
| Phedra Syndelle | Stunts |
| Elizabeth Sparks | Stunts |
| Zhanna Sattsaeva | Stunts |
| Maya Santandrea | Stunts |
| Ayami Sakaeda | Stunts |
| Blanca Rosa Rosario | Stunts |
| Nicole Reddinger | Stunts |
| Jessiqa Pace | Stunts |
| Jessica Medina | Stunts |
| Ingrid Kleinig | Stunt Double |
| Damita Jane Howard | Stunts |
| Brenda Lorena Garcia | Stunts |
| Jessi Fisher | Stunts |
| Katie Eischen | Stunts |
| Courtney Chen | Stunts |
| Sadiqua Bynum | Stunts |
| Danya Bateman | Stunts |
| Kelli Barksdale | Stunts |
| Adrienne Ballenger | Stunts |
| Alina Andrei | Stunts |
| Reetu Aggarwal | 3D Artist |
| James McGrady | Second Unit First Assistant Director |
| Robin Le Chanu | Unit Production Manager |
| Nik Korda | Unit Production Manager |
| Lars P. Winther | First Assistant Director |
| Katy Galow | Second Assistant Director |
| Guy Norris | Second Unit Director |
| Guy Norris | Stunt Coordinator |
| Fiona Campbell Westgate | Visual Effects Producer |
| Bárbara Muschietti | Thanks |
| Bobby James | Stunts |
| K.Flay | Songs |
| Zack Snyder | Executive Producer |
| Michelle Rose | Stunts |
| Clay Cullen | Stunts |
| Freddie Poole | Stunts |
| Eric Stratemeier | Stunts |
| Paul E. Short | Stunts |
| John Roesch | Foley Artist |
| David Swayze | Concept Artist |
