Harley Quinn is a character appearing in American comic books published by DC Comics. She was created by Paul Dini and Bruce Timm for Batman: The Animated Series as a henchwoman for the Joker, and debuted in its 22nd episode, "Joker's Favor", on September 11, 1992. While intended to appear in one episode, Quinn became a recurring character within the DC Animated Universe (DCAU) as the Joker's sidekick and love interest, and was adapted into DC Comics' canon seven years later, beginning with the one-shot Batman: Harley Quinn #1. Quinn's origin story features her as a former psychologist at Gotham City's Arkham Asylum who was manipulated by and fell in love with the Joker, her patient, eventually becoming his accomplice and lover. The character's alias is a play on the stock character Harlequin from the 16th-century Italian theater commedia dell'arte.

Paul McClaran Dini is an American screenwriter and comic creator. He has been a producer and writer for several Warner Bros. Animation/DC Comics animated series, most notably Batman: The Animated Series (1992–1995), and the subsequent DC Animated Universe. Dini and Bruce Timm co-created the characters Harley Quinn and Terry McGinnis.