| Name and firstname(s) | Name Toernooibase | Club or Country |
 Olaerts, Maria | Maria Olaerts | Belgium |
| Olaerts, Paula | Paula Olaerts | Belgium |
| Olaerts, Piet | Piet Olaerts | Belgium |
 Olaniyan, Abdul Mandjide Babatunde Razak | Abdul Mandjide Babatunde Razak Olaniyan | Ivory Coast |
 Olechnovicius, A. | A. Olechnovicius | Lithuania |
 Olejnik, Bernard | Bernard Olejnik | Poland |
| Olejnik, Grazyna | Grazyna Olejnik | Poland |
| Olejnik, Jakub | Jakub Olejnik | Poland |
 Olejnik, Sergey | Sergey Olejnik | Ukraine |
| Olekseenko, Valentina | Valentina Olekseenko | Ukraine |
| Oleksienko, Lidia | Lidia Oleksienko | Ukraine |
| Oleksiuk, Ivan | Ivan Oleksiuk | Ukraine |
| Oleksiuk, Natalia | Natalia Oleksiuk | Ukraine |
 Olenburger, Victoria | Victoria Olenburger | Germany |
 Olimov, Firdavs | Firdavs Olimov | Uzbekistan |
| Olimov, Fitrat | Fitrat Olimov | Uzbekistan |
 Olina, Liva | Liva Olina | Latvia |
 Oliphant, Donald | Donald Oliphant | Great-Britain |
 Olius, Georges | Georges Olius | Haiti |
 Olivan, Thomas | Thomas Olivan | France |
 Olivares, Aureliano | Aureliano Olivares | Dominican Republic |
| Olivares, Victor | Victor Olivares | Dominican Republic |
| Olive, Victorin | Victorin Olive | France |
 Oliveira, Celestino | Celestino Oliveira | Brazil |
| Oliveira, Claudio Gusmao Verdeiro | Claudio Gusmao Verdeiro Oliveira | Brazil |
| Oliveira Massola, Lucas | Lucas Oliveira Massola | Brazil |
 Olivier, C. | C. Olivier | Switzerland |
| Olivo , Dionicio | Dionicio Olivo | Dominican Republic |
| Oliynyk, Kostiantyn | Kostiantyn Oliynyk | Ukraine |
| Oliynyk, Yevhen | Yevhen Oliynyk | Ukraine |
 Olsen, Arthur | Arthur Olsen | USA |
| Olszak, Piotr | Piotr Olszak | Poland |
| Olszewska, Malgorzata | Malgorzata Olszewska | Poland |
 Oluwatoyin, Akinwola | Akinwola Oluwatoyin | Nigeria |
 Omarov, Rustem | Rustem Omarov | Kazachstan |
 Omata, Mitsuo | Mitsuo Omata (28.09.1937 - 21.01.2014) Add info | |
| Omolola Jeje, Awotodunbo | Awotodunbo Omolola Jeje | Nigeria |
| Onashko, Artem | Artem Onashko | Ukraine |
 Onikov, Mikhail | Mikhail Onikov | Russia |
| Onishenko, Ruslan | Ruslan Onishenko | Ukraine |
 Onistjenko, A. | A. Onistjenko | Foreign players |
| Ooghe, Marcel | Marcel Ooghe | France |
 Oostburg, Marcel | Marcel Oostburg | Suriname |
| Opanasuk, Oleksiy | Oleksiy Opanasuk | Ukraine |
| Opdekamp, Danny | Danny Opdekamp | Belgium |
| Opdekamp, Marcel | Marcel Opdekamp | Belgium |
| Opdekamp, Stefan | Stefan Opdekamp | Belgium |
| Operman, Dariusz | Dariusz Operman | Poland |
 Opletal, Martin | Martin Opletal | Czech Republic |
| Oplt, Filip | Filip Oplt | Czech Republic |
| Opryshchenko, Maksym | Maksym Opryshchenko | Ukraine |
| Opulskis, Arturas | Arturas Opulskis | Lithuania |
| Orban, Hubert | Hubert Orban | Belgium |
| Ordies, Pierre | Pierre Ordies | Belgium |
 Ordyan, Rafayel | Rafayel Ordyan | Armenia |
 Orechov, V. | V. Orechov | USSR |
| Oreel, Paul | Paul Oreel | Belgium |
| Ori, Krishnapersad | Krishnapershad Ori | Suriname |
 Orie, Devanand | Devanand Orie | CTD Arnhem |
| Orie, Firosh | Firosh Orie | Suriname |
| Orie, William | William Orie | Suriname |
| Orieshkov, Vladimir | Vladimir Orieshkov | Russia |
| Orihovskiy, Ruslan | Ruslan Orihovskiy | Ukraine |
 Orlenis, Bueno | Bueno Orlenis | Cuba |
| Orlova, Alisa | Alisa Orlova | Latvia |
 Orlova, Viivika | Viivika Orlova | Estonia |
| Orlovska, Evelina | Evelina Orlovska | Latvia |
| Orlow, Agata | Agata Orlow | Poland |
| Ornelis, Maurice | Maurice Ornelis | Belgium |
| Orosin, Dulustan | Dulustan Orosin | Russia |
 Orosz, Reka | Reka Orosz | Hungary |
| Ortikkhujayev, O. | O. Ortikkhujayev | Uzbekistan |
| Oryngaliyev, Sagintay | Sagintay Oryngaliyev | Kazachstan |
| Osadchuk, Volodymyr | Volodymyr Osadchuk | Ukraine |
 Oseana, Patrick | Patrick Oseana | Curacao |
| Osinska, Kinga | Kinga Osinska | Poland |
| Osinski, Bogdan | Bogdan Osinski | Poland |
| Osinski, Dawid | Dawid Osinski | Poland |
| Osiolkowski, Jan | Jan Osiolkowski | Poland |
| Osiolkowski, Piotr | Piotr Osiolkowski | Poland |
| Osipova, Christina | Christina Osipova | Russia |
| Osipovs, Danila | Danila Osipovs | Latvia |
| Ositis, Ricards | Ricards Ositis | Latvia |
 Ossendrijver, J. | J. Ossendrijver | VAD Amsterdam |
| Ost, Armand | Armand Ost | Belgium |
 Ostan , Jonatan | Jonatan Ostan | Slovenia |
 Ostane, Jean Antonio | Jean Antonio Ostane | Canada |
| Ostapenko, Alexey | Alexey Ostapenko | Russia |
 Ostapenko, Olga | Olga Ostapenko | Belarus |
| Ostijn, NN. | NN. Ostijn | Belgium |
| Ostyn, Georges | Georges Ostyn | France |
 Otanazarova, Maftuna | Maftuna Otanazarova | Tadzjikistan |
 Otgonbat, Temuulen | Temuulen Otgonbat | Mongolia |
| Otgonbayar, Enkhbat | Enkhbat Otgonbayar | Mongolia |
| Otgonbayar, Tuvshinbold | Tuvshinbold Otgonbayar | Mongolia |
| Otgonchuluun, Shinezuun | Shinezuun Otgonchuluun | Mongolia |
| Otreppe, d, Martin | Martin d Otreppe | Belgium |
| Otrosjenko, Viktor | Viktor Otrosjenko | Ukraine |
| Ots, J. | J. Ots | Belgium |
| Ottavi, P. | P. Ottavi | France |
