O
- Onoskelis (Testament of Solomon)
- Oray (Christian demonology)
- Orcus
- Orias (Christian demonology)
- Oriax (Christian demonology)
- Ornias (Testament of Solomon)
- Orobas (Christian demonology)
- Orobos (Christian demonology)
- Ose (Christian demonology)
Read more about this topic: List Of Theological Demons