Harley Quinn (Dr. Harleen Quinzel) is a fictional character, a supervillainess, in the animated series Batman: The Animated Series, later adapted into DC Comics' Batman comic books. As suggested by her name (a play on the word "harlequin"), she is clad in the manner of a traditional harlequin jester. The character is a frequent accomplice of Batman's nemesis the Joker, and is also a close ally of supervillainess Poison Ivy.

The character was created by Paul Dini and Bruce Timm and was voiced in the Batman: The Animated Series and its tie-ins by Arleen Sorkin, and most recently by Hynden Walch on The Batman. In the Birds of Prey series, she was portrayed by actress Mia Sara.