- O 'Sullivan Michael E
- Obadia J. F.
- Ochoa-Tapia J Alberto
- Ochoa-Tapia J. Alberto
- Ochoa-Tapia Jesus Alberto
- Odelin Gaelle
- Odelin Gaëlle
- Odic Maxime
- Oeljeklaus Karl
- Oeljeklaus Karl
- Ohana Noé
- Okada Izumi
- Okamoto Naoya
- Okonek Christian
- Okonek Christian
- Oksanen L
- Olimpieri Federico
- Olimpieri Federico
- Olive Daniel
- Olive Guillaume
- Olive Marc
- Oliveau Sébastien
- Oliveira Jorge
- Olivier Brett
- Olivier Eric
- Olivier J
- Olivier Julien
- Olivier Julien
- Olivier Éric
- Olivieri Enzo
- Ollinger Nicolas
- Ollinger Nicolas
- Olshanski Grigori
- Olympio Anani Ayodélé
- Omer Harold
- Omi Shizue
- Onchis Darian M.
- Onchis-Moaca Darian
- Onishi Ryo
- Opdam Eric
- Oppenheim Georges
- Oppenheim Georges
- Oprocha Piotr
- Orenshtein Tal