O
- (Owan West) Oke
- (Uhunmwonde) Oke
- (Ikpoba-Okha) Okavborhan
- (Ikpoba-Okha) Okavbogu
- (Ovia North-East) Okanya
- (Uhunmwonde) Okakhinawan
- (Esan South-East) Okaigben
- (Uhunmwonde) Okahmavwen
- (Owan West) Okagboro
- (Owan West) Okafu
- (Ikpoba-Okha) Okabere
- (Ovia North-East) Okabeghe
- (Ikpoba-Okha) Oka
- (Ovia South-West) Ojogbede
- (Akoko-Edo) Ojirami Oke
- (Akoko-Edo) Ojirami Ogbo
- (Akoko-Edo) Ojirami
- (Etsako East) Ojeaga
- (Akoko-Edo) Oja Sale
- (Akoko-Edo) Oja
- (Ovia North-East) Ohogua
- (Ikpoba-Okha) Ohoghobi
- (Ikpoba-Okha) Ohere
- (Ikpoba-Okha) Ohen
- (Uhunmwonde) Ohe
- (Orhionmwon) Oheze-Naka
- (Ikpoba-Okha) Oha
- (Esan West) Ogwa
- (Etsako East) Ogute
- (Egor) Ogunwenyi