| Onta, Pushpa Raj |
| Onta, Utcrist Raj |
| Onuma Wongsangam |
| Onwudinjo, Chimezie Frank |
| Oo Ko Ko Htike |
| Oo Oo Khin |
| Ooi, Hoow Kiong |
| Oongart Pornkarnchananun |
| Opal Prakobboon |
| Oparaocha, Sheila Ngozi |
| Opas Ovasith |
| Opath Dumnernnirun |
| Opathella, Ganehi Kankanamalage Chandrabhanu |
| Ophetsane, Phoumy |
| Opiniano, Napoleon M., Jr. |
| Opiso, Earl Macamay |
| Oppus, Beatriz Nicolle Ablat |
| Ora Rojanastien |
| Orachat Kaothien |
| Orachorn Punyajaray |