Margot Robbie Harleen Quinzel / Harley Quinn Ewan McGregor Roman Sionis / Black Mask Mary Elizabeth Winstead Helena Bertinelli / Huntress Jurnee Smollett Dinah Lance / Black Canary Rosie Perez Detective Renee Montoya Chris Messina Victor Zsasz Ella Jay Basco Cassandra Cain Ali Wong Ellen Yee Matthew Willig Happy Dana Lee Doc Steven Williams Patrick Erickson Robert Catrini Stefano Galante Daniel Bernhardt Sionis' Chauffeur François Chau Mr. Keo Miyuki Matsunaga Mrs. Keo Anna Mikami Miss Keo Paul Lasa Franco Bertinelli Charlene Amoia Maria Bertinelli Ella Mika Young Helena Bertinelli Derek Wilson Tim Evans Bojana Novaković Erika Andy Hoff Erika's Date Bruno Oliver Sal Michael Masini Officer Dargo Judy Kain Bespectacled Secretary David Bianchi Henchman Rj Wayne Tough Guy Eddie Alfano Helena's Bodyguard Sala Baker Prisoner Karen Teliha Nun Nev Smith Gotham Detective Anthony Molinari Mafiosi Jeff Lipary BBB Gang Member Eddie J. Fernandez Gauntlet Cop Tim Rigby RR Passenger Richard King Mercedes Gang Sam Hargrave Mercenary Efka Kvaraciejus Mercenary Buddy Sosthand Coffee Cup Cop