| Link | Location |
|---|
 | Pavel Osin | Moscow, Russian Federation |
| Ilona Osińska | Warszawa, Poland |
| Kamil Osiński | Warszawa, Poland |
| Miłosz Osiński | Warszawa, Poland |
| Ezgi Osmanoglu | Munich, Germany |
| Paweł Osmólski | Kraków, Poland |
| Ivie Osobase | Live online from Sydney, Australia |
 | Edgardo Osorio González | Santiago, Chile |
| Magdalena Ostalska | Warszawa, Poland |
| Alena Ostanina | Astana, Kazakhstan |
| Devin Osterhout | Salt Lake City, Utah, United States |
| Amanda Österling | Warsaw, Poland |
| Aleksandr Ostroukhov | Saint-Petersburg, Russian Federation |
| Andrzej Ostrowski | Wrocław, Poland |
 | Alberto Osuji | Lagos, Nigeria |
