New Entry
 |  | Name | Creator | Significance | Score |
|---|---|---|---|---|---|
| Of Curses and Odd Hair Colors | esantin | Central | 32 | |
| | Oglaf | Trudy Cooper, Doug Bayne | Minor | 8 |
| Oh! My Goddess | Fujishima Kosuke | Minor | 4.8 | |
| One Piece | Oda Eiichirō | Trivial | 2 | |
| Ouran High School Host Club | Hatori Bisco | Central | 19.4 | |
| Ouran High School Host Club | Hatori Bisco | Central | 14.4 | ||
| Outlaw Star | Itō Takehiko, Hongō Mitsuru | Minor | 4 | |
| Overlord | Chibi-Reaper | Major | 15.2 | |
| Ozy and Millie | D.C. Simpson | Minor | 12 |