| Name | Country | Feature class | Latitude | Longitude | |
|---|---|---|---|---|---|
2801  | River Osun  Awba,Awbe,Oshun,Oshun River,Osun River,River Oshun,River Osun | Nigeria, | stream | N 6° 33′ 35'' | E 4° 3′ 46'' |
2802  | Osasimwinoba Osasimwinoba,Osasinmoba,Osesunmoba | Nigeria, Edo State Ovia North-East | populated place | N 6° 33′ 50'' | E 5° 44′ 30'' |
| 2803 | Orudu-Olokan Ordu-Olokan,Orudu,Orudu-Olokan | Nigeria, Ogun State Ifo | populated place | N 6° 44′ 31'' | E 3° 19′ 45'' |
| 2804 | Oruba Agboyi,Oruba,Oruba Agboyi | Nigeria, Lagos Kosofe | populated place | N 6° 34′ 36'' | E 3° 24′ 35'' |
| 2805 | Urowa Orowa,Urowa | Nigeria, Edo State Esan South-East | populated place | N 6° 30′ 25'' | E 6° 32′ 24'' |
2806  | Oroni | Nigeria, | oilfield | N 5° 20′ 0'' | E 6° 10′ 0'' |
| 2807 | Oroghe Ologhe,Oroghe | Nigeria, Edo State Iguegben | populated place | N 6° 28′ 46'' | E 6° 14′ 8'' |
| 2808 | Orogbo-Olamodi Orogbo Lamodi,Orogbo-Lemodi,Orogbo-Olamodi | Nigeria, Ogun State Obafemi Owode | populated place | N 6° 55′ 55'' | E 3° 24′ 14'' |
| 2809 | Orita-Bodun Ajebandele,Orita,Orita-Bodun | Nigeria, Lagos Epe | populated place | N 6° 36′ 27'' | E 3° 52′ 23'' |
| 2810 | Orile-Owu Ago-Owu,Orile Owu,Orile-Owu | Nigeria, Osun State Aiyedade | populated place | N 7° 14′ 54'' | E 4° 19′ 49'' |
| 2811 | Orile-Igbein Igbein,Orile-Igbehin,Orile-Igbein | Nigeria, Ogun State Obafemi Owode | populated place | N 6° 52′ 50'' | E 3° 30′ 40'' |
| 2812 | Orho-Agbarho Agbadu,Agbarho,Orho-Agbarho | Nigeria, Delta Ughelli North | populated place | N 5° 35′ 30'' | E 5° 51′ 48'' |
| 2813 | Oregun Okori Egun,Oregun | Nigeria, Lagos Eti Osa | populated place | N 6° 29′ 11'' | E 3° 37′ 54'' |
| 2814 | Ulapata Orabuta,Oraputa,Ulapata | Nigeria, Rivers State Ahoada East | populated place | N 5° 5′ 21'' | E 6° 37′ 31'' |
| 2815 | Oroma Otu Orania-Otu,Oroma Otu,Oronia-Utu | Nigeria, Anambra Anambra West | populated place | N 6° 30′ 35'' | E 6° 51′ 40'' |
| 2816 | Opuadana Opuadana,Opuadona,Opugbene | Nigeria, Bayelsa State Southern Ijaw | populated place | N 4° 34′ 6'' | E 5° 52′ 43'' |
| 2817 | Opaji Opaji,Opoji | Nigeria, Edo State Esan Central | populated place | N 6° 41′ 11'' | E 6° 11′ 58'' |
| 2818 | Opobo Opobo,Opobo Town | Nigeria, Rivers State | seat of a second-order administrative division | N 4° 30′ 50'' | E 7° 32′ 16'' |
| 2819 | Ugbekele Waterside Opekeli,Ugbekele,Ugbekele Waterside,Upekeli | Nigeria, Edo State | populated place | N 5° 59′ 1'' | E 5° 47′ 20'' |
| 2820 | Onyuwei Onuweyi,Onyue,Onyuwei | Nigeria, Benue State Oturkpo | populated place | N 7° 2′ 41'' | E 8° 3′ 29'' |
| 2821 | Oyin Akoko Onyin,Onyin Akoko,Oyin Akoko | Nigeria, Ondo State Akoko North West | populated place elevation 485m | N 7° 40′ 24'' | E 5° 45′ 24'' |
| 2822 | Onugba Enugba,Onugba,Onugwa | Nigeria, Benue State Agatu | populated place | N 7° 52′ 2'' | E 7° 50′ 19'' |
| 2823 | Onu Anyim Agbaja,Onu Anyim,Onuanyim | Nigeria, Ebonyi State Izzi | populated place | N 6° 43′ 43'' | E 8° 13′ 44'' |
| 2824 | Ositu Onilu,Onitu,Ositu | Nigeria, Rivers State Ahoada West | populated place | N 5° 4′ 59'' | E 6° 28′ 28'' |
| 2825 | Onidjor Egbo-Uwheru Egbo-Uwheru,Onidjor,Onidjor Egbo-Uwheru | Nigeria, Delta Ughelli North | populated place | N 5° 20′ 37'' | E 6° 3′ 47'' |
| 2826 | Omu-Ipetu Ipetu,Omu Ipetu,Omu-Ipetu | Nigeria, Kwara State Irepodun | populated place | N 8° 5′ 56'' | E 5° 5′ 1'' |
| 2827 | Omu-Aran Omu,Omu-Aran | Nigeria, Kwara State Irepodun | seat of a second-order administrative division population 14,477 | N 8° 8′ 1'' | E 5° 6′ 1'' |
| 2828 | Omo Forest Reserve | Nigeria, Ogun State | forest reserve | N 6° 50′ 49'' | E 4° 22′ 17'' |
| 2829 | Omin-Adio Adio Station,Omin Adio,Omin-Adio | Nigeria, Oyo State Ido | populated place | N 7° 23′ 31'' | E 3° 45′ 14'' |
| 2830 | Oluwo-Akeusi Ayedi,Oluwo Akeusi,Oluwo-Akeusi | Nigeria, Ogun State Odeda | populated place | N 7° 9′ 47'' | E 3° 33′ 17'' |
| 2831 | Olude-Araromi Olude,Olude Araromi,Olude-Araromi | Nigeria, Oyo State Ido | populated place | N 7° 28′ 57'' | E 3° 50′ 19'' |
| 2832 | Oloyo-Oso Awshaw,Oloyo Oso,Oloyo-Oso | Nigeria, Ogun State Odeda | populated place | N 7° 19′ 53'' | E 3° 42′ 53'' |
| 2833 | Olowo Belo-Olowo,Beto-Olowo,Olowo | Nigeria, Oyo State Ori Ire | populated place | N 8° 20′ 38'' | E 4° 19′ 25'' |
| 2834 | Olotu Olote,Oloten,Olotu | Nigeria, Edo State Orhionmwon | populated place | N 6° 13′ 18'' | E 6° 5′ 4'' |
| 2835 | Okporokiri Okparakiri,Okporokiri,Olomaboko | Nigeria, Rivers State Akuku Toru | populated place | N 4° 23′ 43'' | E 6° 49′ 41'' |
| 2836 | Olokemeji Forest Reserve | Nigeria, | forest reserve | N 7° 24′ 29'' | E 3° 32′ 14'' |
| 2837 | Oloka One Awlawka,Oloka,Oloka I,Oloka One | Nigeria, Ogun State Imeko Afon | populated place | N 7° 25′ 27'' | E 2° 55′ 34'' |
2838  | Oloja Hill Alawja Hill,Oloja Hill | Nigeria, Oyo State Afijio | hill | N 7° 42′ 56'' | E 3° 50′ 10'' |
| 2839 | Olihlin Olihlin,Olili | Nigeria, Edo State Esan North-East | populated place | N 6° 48′ 56'' | E 6° 24′ 45'' |
| 2840 | Oligie Oligi,Oligie | Nigeria, Edo State Orhionmwon | populated place | N 6° 19′ 53'' | E 6° 13′ 11'' |
| 2841 | Old-Gwam-Gwam Gwamgwam,Old Gwam Gwam,Old-Gwam-Gwam | Nigeria, Nasarawa State Toto | populated place | N 8° 16′ 51'' | E 6° 58′ 51'' |
| 2842 | Old Gendinni Old Gedenni,Old Gendinni,Tungan Gendenni | Nigeria, Kebbi Bagudo > Kaoje Gwamba | populated place | N 11° 20′ 1'' | E 4° 8′ 49'' |
| 2843 | Ola Ola,Olah,Olo | Nigeria, Kogi State Dekina | populated place | N 7° 34′ 8'' | E 7° 26′ 31'' |
| 2844 | Okuidiemoo Okuidiemo,Okuidiemoo,Okwuidiemo | Nigeria, Delta Okpe | populated place | N 5° 39′ 48'' | E 5° 46′ 44'' |
| 2845 | Okwaraka Okuraka,Okwaraka,Okworeka | Nigeria, Ebonyi State Izzi | populated place | N 6° 28′ 12'' | E 8° 14′ 5'' |
| 2846 | Okunron Okunran,Okunron,Okurun | Nigeria, Kogi State Yagba West | populated place | N 8° 17′ 26'' | E 5° 27′ 8'' |
| 2847 | Okunegun Egun,Oke Egun,Okoyogun,Okunegun | Nigeria, Lagos Ibeju Lekki | populated place | N 6° 30′ 49'' | E 3° 53′ 34'' |
| 2848 | Oku Lake | Nigeria, Benue State | lake | N 7° 56′ 0'' | E 8° 48′ 0'' |
| 2849 | Okulu River Akura River,Eruku,Eruku River,Okulu,Okulu River,Okura,River Okoro,River Okula | Nigeria, Kogi State | stream | N 7° 2′ 48'' | E 7° 5′ 16'' |
| 2850 | Okubio Ikubio,Okubie,Okubio,Ukubio | Nigeria, Bayelsa State Southern Ijaw | populated place | N 4° 41′ 10'' | E 5° 50′ 8'' |
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