| Name | Total | ... |
|---|---|---|
| Olivia | 1 | GO |
| Olivia (Pokemon) | 1 | GO |
| Olivier Mira Armstrong | 4 | GO |
| Olminu | 0 | GO |
| Omar al-Bashir | 1 | GO |
| Omiko Hakodate | 3 | GO |
| One | 1 | GO |
| One-san (Penguin Highway) | 0 | GO |
| Onimaro | 1 | GO |
| Onna Kishi | 6 | GO |
| Onna Mahoutsukai | 1 | GO |
| Onodera Haru | 4 | GO |
| Onodera Kosaki | 16 | GO |
| Ononoki Yotsugi | 9 | GO |
| Onozuka Asahi | 4 | GO |
| Onpu Segawa | 2 | GO |
| Onsa Amano | 3 | GO |
| Ooi | 17 | GO |
| Oolong | 2 | GO |
| Ooshio | 1 | GO |
| Ooyodo | 16 | GO |
| Oozora Subaru | 1 | GO |
| Operator 21O | 2 | GO |
| Operator 6O | 1 | GO |
| Ophelia Phamrsolone | 1 | GO |
| Ophiuchus Shaina | 2 | GO |
| Orange Pekoe | 14 | GO |
| Orba | 1 | GO |
| Orchid / Orchis | 2 | GO |
| Orga Itsuka | 2 | GO |
| Oriana Thomson | 9 | GO |
| Origami Tobiichi | 2 | GO |
| Original | 1 | GO |
| Orihime Inoue | 46 | GO |
| Orion/Artemis | 2 | GO |
| Orochi | 5 | GO |