List of People
| Display Name | Surnames | Given Names | Gender | Nationality | |
|---|---|---|---|---|---|
| ONOFRIIUK Maksym | Onofriiuk | Maksym | M | UKR | |
| ONOPKO Polina | Onopko | Polina | F | UKR | |
| ONYEKWUE NNAJI Joshua | Onyekwue Nnaji | Joshua | M | GER | |
| OONK Emmeliene | Oonk | Emmeliene | F | NED | |
| OOSTENRIJK Sophia | Oostenrijk | Sophia | F | NED | |
| OOSTHOEK Jetze | Oosthoek | Jetze | M | NED | |
| OOSTINDIE Hans | Oostindie | Hans | M | NED | |
| OPAČIĆ Nenad | Opačić | Nenad | M | SRB | |
| OPHEY Clemens | Ophey | Clemens | M | GER | |
| ÖQVIST Amanda | Öqvist | Amanda | F | ||
| ORAN Muhammet | Oran | Muhammet | M | TUR | |
| ORBAKAS Matas | Orbakas | Matas | M | LTU | |
| ORBAN Louis | Orban | Louis | M | BEL | |
| ORBÓK Réka | Orbók | Réka | F | HUN | |
| O'REAGAN Ruadhan | O'Reagan | Ruadhan | M | WAL | |
| O'REGAN Ruadhan | O'Regan | Ruadhan | M | WAL | |
| O'REGAN Aodhan | O'Regan | Aodhan | M | WAL | |
| O'REGAN Alex | O'Regan | Alex | M | IRL | |
| O'REILLY Hilary | O'Reilly | Hilary | F | IRL | |
| O'REILLY Claire | O'Reilly | Claire | F | IRL |