- Obenchain Daniel A
- Oberfeld Daniel
- O’brien Marie
- O'Brien Marie
- Ocampo-Martinez Carlos
- Oge Anthony
- Oillo Benoit
- Okassa Mfoubat Anicet
- Olesen Nina
- Olive Enrick
- Olivier Anne-Hélène
- Ollinger Eric
- Olny Xavier
- Olsson Emelie
- Olsson Emelie
- Olteanu Ana Maria
- Olteanu Ana-Maria
- Olteanu-Raimond Ana-Maria
- Olzmann Matthias
- Omenzetter Piotr
- Omikrine Metalssi Othman
- Onanena Raissa
- O'Neill Conor
- Onfroy Thomas
- Orfeuil Jean–pierre
- Orfila O.
- Orfila Olivier
- Orfila Olivier
- Orlando Victoria
- Orlando Victoria
- Orlando Victoria M
- Orr-Ewing Andrew
- Ortiz Miguel
- Ortiz Miguel
- Orus Jean-Pierre
- Osborn David
- Osborn David
- Oser Antoine
- Oseth Svend-Peder
- Oslo Asa
- Osman Martin
- Osman M
- Ossikovski Razvigor
- Ostachowicz Wieslaw
- Otaegui Oihana
- Othman Amine
- Othman Dhouha
- Otte D
- Otto Gustavo Garcia
- Oudar Jean-Louis
- Ouedraogo Abel
- Ouedraogo Kiswendsida Abel
- Oueidat Mohamad
- Ouerhani Yousri
- Oueslati Walid
- Ouhab Merouane
- Ou Jinping
- Oukhellou Latifa
- Oukhellou Latifa
- Oukhellou L.
- Ould Bouamama Belkacem
- Ourir Abdelwaheb
- Ousten Jean-Pierre
- Outbib Rachid
- Oxley Jennifer
- Ozols Kaspars
- Ozuem Chukwuka