| Link | Location | |
|---|---|---|
 | Piotr Opalacz | Kraków, Poland |
| Pavel Oparin | Almaty, Kazakhstan |
| Yulia Openysheva | Moscow online, Russian Federation |
| Douglas Opfer | Houston, Texas, United States |
| Bas Opgelder | Hoofddorp, Netherlands |
| Heino Ophey | Karlsruhe, Germany |
| Luca Oppedisano | Turin, Italy |
| Thomas Oppermann | Berlin, Germany |
| Gabriela Oprea | Bucharest, Romania |
| Robert-Jan Opschoor | Den Haag, Netherlands |
| Adam Or | Hong Kong, Hong Kong |
.jpg){kind=avatar} | Alina Orasanu | Munich, Germany |
| Jouko Orava | Vaasa, Finland |
 | Marta Orbitowska | Szczecin, Poland |
| Andrés Orduz | Brussels, Belgium |
