Official:
Shojo Beat
Ouran High School Host Club (Funimation)
Ouran Koukou Host Club Anime (Japanese)
Ouran Koukou Host Club @ VAP (Japanese)
Hakusensha Online (Japanese)
Bones Studio (Japanese)
Ouran Video Game (Japanese)
Anime News Network
General Sites:
Debt - General series
Ouran Koukou RP - Role-playing forum
Mata Ashita! - Fanfiction Archive
Hanami - Roleplaying Journals
Character Shrines:
Adorable King - Tamaki Suoh
Relatively Normal - Kaoru Hitachiin
General LJ Communities:
Ouran Academy
Ouran High School Host Club Slash
Ouran Koukou Host Club Community
Ouran Koukou Host Club Claims
Ouran Koukou Host Club Fanfiction
Ouran Koukou Host Club Icons
Ouran Koukou Host Club Rating Community
Ouran Parody LJ Community
Challenge LJ Communities:
Ouran 100 - Drabbles
Ouran Host Club Flashfic - Short fanfics
Characters/Relationships LJ Communities:
Hidden in the Shadows - Kyoya/Haruhi
Hikaru & Haruhi - Hikaru/Haruhi
Hikaru/Haruhi/Kaoru OT3 - Hikaru/Haruhi/Kaoru
It Takes Two - Hikaru/Kaoru
Kyouya & Tamaki - Kyoya/Tamaki
Mori x Honey - Mori/Hunny
Romantic Comedy - Tamaki/Haruhi
Tamaki Love - Tamaki Suoh
Very Good Curses - Umehito Nekozawa
Fanlistings:
Egotistical Club - Hatori Bisco
Insightful - Kyoya Ohtori
Itsumo Soba ni - Takashi Morinozuka
Kawaisa - Mitsukuni Haninozuka
King at Heart - Tamaki Suoh
Lost Kitten - Kirimi Nekozawa
Loving Okama - Ryoji "Ranka" Fujioka
Mischief-maker - Hikaru Hitachiin
Nocturnal Shadows - Black Magic Club
Peculiar Persona - Umehito Nekozawa
Power of One - Hikaru Hitachiin
Priceless - Host Club
Relatively Normal - Kaoru Hitachiin
Renge Fanlisting - Renge Houshakuji
Unlikely Heroine - Haruhi Fujioka
Relationship Fanlistings:
A Light in Your Dark - Umehito Nekozawa and Kirimi Nekozawa
Daughter, Mommy, and Daddy - Haruhi Fujioka, Kyoya Ohtori, and Tamaki Suoh
Devoted - Mitsukuni Haninozuka and Takashi Morinozuka
Everything to Gain - Kyoya Ohtori and Haruhi Fujioka
Familial Duty - Tamaki Suoh and Kyoya Ohtori
Kawaii Appreciation - Tamaki Suoh and Mitsukuni Haninozuka
Mitsuketa - Hikaru Hitachiin and Haruhi Fujioka
Mittsu Kawaii - Tamaki Suoh, Haruhi Fujioka and Mitsukuni Haninozuka
Otaku Fantasy - Kyoya Ohtori and Renge Houshakuji
Pas de Deux - Hikaru Hitachiin and Kaoru Hitachiin
Romantic Comedy - Tamaki Suoh and Haruhi Fujioka
Silent Adoration - Takashi Morinozuka and Haruhi Fujioka
Stimulating Symmetry - Hikaru Hitachiin, Haruhi Fujioka, and Kaoru Hitachiin
Smily (It's Cute!) - Mitsukuni Haninozuka and Haruhi Fujioka
Unfated - Ritsu Kasanoda and Haruhi Fujioka