Harley Quinn's Heaven  
   Comprehensive fan site with profiles, merchandise, appearances.
   http://www.angelfire.com/tv/harleyquinn

Harley Quinn HQ  
   Character biographies, essays, fan fiction, fan art, images, sounds, Arkham Asylum files.
   http://www.harleyquinnhq.com/

Collecting Harley Quinn  
   An informative fan site with currents news, previews and comic appearances.
   http://www.geocities.com/collecting_harley/

Harley's Room  
   Fan site with information on Harley Quinn, The Joker, Poison Ivy and Batman. Includes profiles, casting calls and photos.
   http://harleyquinn.lunaticsworld.com/

Gotham Girls  
   An on going web toon written by Paul Dini and centered on the adventures of Harley Quinn, Poison Ivy, Catwoman and Batgirl.
   http://www.gothamgirls.com

Harley's Haven  
   Fan site with quotes, facts, comic book summaries, FAQ.
   http://harley-quinn.com/

Mad Love Asylum  
   The second unofficial fan club dedicated to Harley Quinn. Forums with discussions on comics, animation, websites, fiction and art.
   http://madloveasylum.proboards21.com/