- Obadia Thomas
- Obame-Nkoghe Judicaël
- Obare Peter
- Obenga Gaëlle
- Oboho Ikwo
- O'Connell Jeffrey R
- O'Connor Olivia
- Octobre Sylvie
- Odonne G.
- Oeung Kunthea
- Officer Kirsty
- Officer Kirsty
- Oguike Mary
- Ogutu Bernhards
- Ohlsson Claes
- Ohlstein Laurie
- Ojo Kayode K.
- Okafor Obiageli
- Okomo Marie-Claire Assoumou
- Oksenhendler Éric
- Oladipo Jamiu O.
- Oldehinkel Albertine J
- Oliva Clélia F
- Oliveira Fabiano
- Olliaro Piero
- Olliaro Piero L.
- Ollomo Benjamin
- Olson Sarah
- Olson Sarah H.
- Omaliss Keo
- O’neill Sandra
- Ong Ken K
- Ong Sivuth
- Onyor Pamela
- Ooi Mong How
- Oo Khin Yi
- Oo Nwe Nwe
- Oostra Ben A
- Orivel Jérôme
- Orjuela-Sánchez Pamela
- Ork M.
- Ork Vichit
- Orne-Gliemann Joanna
- Osbjer Kristina
- Osman Said Mohamed
- Osorio Lyda
- Osuna-Cabello Maria
- Otam Laure
- Otienoburu Sabina Dahlström
- Otoo Sampson
- Ouedraogo Abdoul Salam
- Ouedraogo Abdoul-Salam
- Ouédraogo Jean-Bosco
- Ouedraogo Macaire
- Ouedraogo Saidou
- Ouedraogo Samiratou
- Ouji Manel
- Ouk Sivkeng
- Ouk Vara
- Ould Elmamy Bezeid
- Oum Mengheng
- Oung Chakravuth
- Ouoba Serge
- Oussiguéré Assandi
- Ou Teyputita
- Ou Tey Putita
- Ou T.P.
- Overballe-Petersen Søren
- Overgaard Hans J.
- Overtoom Rob
- Overtoom Rob
- Oyas Harry
- Oyibo Wellington