Harleen Quinzel used to study behaviour of zoology at S.T.A.R. Labs. One of her tasks was to calm down Titano for his training in space flight. Eventually, she would grow to be a psychiatrist in Arkham Asylum, which led to her encounter with The Joker. After donning the Harley Quinn persona, she allies herself with Poison Ivy to commit several crimes.
- This version of the character is exclusive to the continuity of the television series Justice League Action and is an adaptation of Harleen Quinzel/Harley Quinn. The original character was created by Paul Dini and Bruce Timm and first appeared in the episode "Joker's Favor" of the series Batman.
- Harley Quinn is voiced by Tara Strong.
- 6 Appearances of Harleen Quinzel (Justice League Action)
- 4 Images featuring Harleen Quinzel (Justice League Action)
- Quotations by or about Harleen Quinzel (Justice League Action)
- Character Gallery: Harleen Quinzel (Justice League Action)