| Nurgle(noun, fictional, naming, demons) |
| O Tokata(noun, name, mythology, Indonesian, indonesian) |
| Odio(noun, name, fictional, demons) |
| Old Ones(noun, name, fictional, demons) |
| Ordog(noun, name, mythology, Hungarian, hungarian) |
| Orias(noun, demons, christian, theological) |
| Oriax(noun, demons, christian, theological) |
| Ormendhal(noun, name, fictional, demons) |
| Orobas(noun, demons, christian, theological) |
| Ose(noun, demons, christian, theological) |
| Other Mother(noun, name, fictional, demons) |
| Overlord Baal(noun, name, fiction, demons) |
| Oyashiro(noun, name, fictional, demons) |
| Paimon(noun, demons, christian, theological) |
| Pascal(noun, name, fictional, demons) |
| Peaches(noun, name, fictional, demons) |
| Pelesit(noun, name, mythology, Indonesian, indonesian) |
| Phenex(noun, demons, christian, theological) |
| Piccolo(noun, name, fictional, demons) |
| Pinhead(noun, name, fictional, demons) |