Regions of Nigeria
- Olakanmi
- Olajogun
- Olajide
- Olaji
- Olaho
- Olague Creek
- Olaegbe
- Oladeji
- Ola
- Ola
- Ola
- Okwuzi
- Okwuta
- Okwuohia
- Okuidiemo
- Okwudo
- Okwu
- Okpoga
- Okwoengele
- Okwo
- Okwele
- Okwefurike
- Okwe
- Okwe
- Okwe
- Okwargoun
- Okwaregi
- Okwaraka
- Okwara Hill
- Okwangwo
- Okwale
- Okwa Junction
- Okwagbe Inland
- Okwagbe
- Okwagbe
- Okwadiokpara
- Okwaba
- Okwa
- Okwa
- Okwa
- Okuzuwa
- Okuvo
- Okutukutu
- Okutu
- Okuta
- Okuta
- Okesubu
- Okusikiri
- Okolovu
- Okurogba
- Okuro
- Okurike
- Okurike
- Okurekpo
- Okura Hill
- Okura Iyale Forest Reserve
- Okuovwori
- Okuovu Inland
- Okuovu
- Okuotomewo
- Oku-Omoni
- Okuokpokpor
- Okuoke
- Okuogholo
- Okuodede
- Okuobadjere
- Okuo
- Okunyeonu
- Okunsolu
- Okunron
- Okun-Owa
- Okunola
- Okunoh
- Okuno
- Okunmo
- Okunkungi
- Okun Isoku
- Okuni
- Okunegun
- Okundi
- Okunbiri
- Okunaja
- Okunade
- Okumurutet
- Okume
- Okume
- Okumbiri
- River Okumase
- Okuma
- Okuno
- Okulegbee Stream
- Oku Lake
- Okulu River
- Okuku Railway Station
- Okukuk
- Okuku
- Okuku
- Okuku
- Okuko
- Okuje
- Okuijorugu
- Okuohorhe
- Okwugbogbo
- Okugbe
- Okugbaja
- Okuetolor
- Oku Enyi
- Okuenebele
- Okuemaife
- Okuegba
- Okuda
- Okubushoyo
- Okuedafe
- Okubiyi
- Okubiyi
- Okubie
- Okubiakri Creek
- Okuba
- Okuama
- Okuabude
- Okua
- Okua
- Okua
- River Okwu
- Oku
- Oku
- Oku
- Okruke-Nkum
- Okirka Creek
- Okrika Arm
- Okrika
- Okrika
- Okrika
- Okrigo
- Okpuwo-Imeze
- Okpuruta
- Okpura-Egbu
- Okpuno-Awka
- Okpulukpu
- Okpuitomo
- Okpueze-Umumba
- Okpudu
- Okpuala
- Okpuala
- Okpu
- Okpotuwari
- Okpotububo
- Okpotububo
- Okpotoku Camp
- Okpoto
- Okpoto
- Okposo
- Okposi
- Okposi
- Okposhi-Mgbo
- Okporporo
- Okporowo
- Okporoma
- Okporojo
- Okporo-Enyi
- Okporo
- Okporo
- Okporo
- Okporku
- Okporakhor
- Okponyo
- Okponha
- Okpon
- Okpoma
- Okpoma
- Okpolo River
- Okpokunu
- River Okpoku
- River Okpoku
- Okpoku
- Okpokong
- Okpoko River
- Okpokiri
- Okpokiri
- Okpok Ikpa
- Okpokhumi
- Okpoha
- Okpogho
- Okpofe
- Okpo-Ezi
- Okpoduma
- Okpoduma
- Okpodom
- Okpodom
- Okpo River
- River Okpo
- Okpo
- Okpo
- Okpo
- Okpo
- Okpo
- Okpo
- Okpiniama
- River Okpikpi
- Okpetumo