- Oldehinkel Albertine J
- Olden Matthias
- Oldrini G.
- Olivari-Philiponnet Camille
- Olivié Damien
- Ollier Bill
- Ollivier-Hourmand I.
- Olsen Anja
- Olsson Christian
- Ong Ken K
- Onland-Moret N. Charlotte
- Onraed Brigitte
- Oostra Ben A
- Orban Thomas
- Orcel Philippe
- Ordás I.
- Orione Clement
- Ortega-Deballon Pablo
- Ospina-Arango Juan D.