- Osai Justina Ojigho
- Osai Ojigho
- Osarhieme George
- Osaze Lanre Nosaze
- Oscar D. Simela
- Oscar Fortin
- Oscar H. Blayton
- Oscar Ramjeet
- OSI Angola, AJPD
- Osita Ebiem
- Osiwa
- Osman D. Osman
- Osman Naway
- Osman Nawy
- Ota Benga Alliance
- Otiato Guguyu
- Otieno Orwa
- Otim Denis Barnabas
- Otsieno Namwaya
- Otsieno Namwaya and Elizabeth Evenson
- Otto Saki
- Ouédraogo Aïcha
- Ouestaf News
- Ouko Eunice Wambui
- Ouma Kizito Ajuong
- Oumoul Khayri Niang Mbodj
- Oupa Lehulere
- Ouraga Obou
- Ousmane Sy
- Ousmane Tanor Dieng
