Participants
| Edwin Obaje | Nigeria |
| Chikwelu Lawrence Obi | South Africa |
| Duván Ocampo | Colombia |
| George Ogoh | Nigeria |
| Seung Oh | Korea, Republic of |
| Bolanle Ojokoh | Nigeria |
| John Okumu | Kenya |
| Judit Oláh | Hungary |
| Vashulenko Oleksandra | Ukraine |
| Hayet Omri | Tunisia |
| Roman Ondráček | Czech Republic |
| Tolullah Oni | United Kingdom |
| Krisztina Ónodi | Hungary |
| Camila Ordoríca | Mexico |
| Ferenc Orosz | Hungary |
| Esther Orozco | Mexico |
| Athar Osama | Pakistan |
| Hossam Eldin Osman | Egypt |
| Erika Ospina Rozo | Colombia |
| Anna Otabil | Ghana |
| Mazlan Othman | Malaysia |
| Peggy Oti-Boateng | |
| Farah Ouechtati | Tunisia |
| Mahama Ouedraogo | Ethiopia |