| Name | ELO | Title | Federation | Games |
| O'Brien, Kieran | 1773 |  Ireland |
11 | |
| O'Brien, Richard | 2080 | Ireland |
1 | |
| O'Cinneide, Mel | 2245 | Ireland |
9 | |
| O'Connell, Gerard | 2148 | Ireland |
24 | |
| O'Connell, Kevin J | 2328 | FM | Ireland |
9 |
| O'Connor, Jonathan | 2242 | Ireland |
8 | |
| O'Connor, Joseph | 2065 |  United Kingdom |
7 | |
| O'Donnell, Robert | 1986 |  United States |
6 | |
| O'Donnell, Tom | 2332 | IM |  Canada |
18 |
| O'Donovan, Richard | 2097 | Ireland |
13 | |
| O'Driscoll, Kieran | 2081 | Ireland |
46 | |
| O'Grady, Gary | 1932 | Ireland |
7 | |
| O'Leary, Matt | 2053 | Ireland |
9 | |
| O'Reilly, Edward | 2240 | Ireland |
8 | |
| O'Rourke, Ray | 1931 | Ireland |
9 | |
| O'Shaughnessy, Conor | 2209 | Ireland |
8 | |
| O'Shea, Kevin | 2035 | Ireland |
10 | |
| Oancea, Nicolae | 2089 |  Romania |
11 | |
| Oates, David | 2166 |  Wales |
21 | |
| Oatlhotse, Providence | 2212 | IM |  Botswana |
80 |
| Obad, Andrija | 2277 |  Bosnia And Herzegovina |
11 | |
| Obad, Damir | 1983 |  Croatia |
6 | |
| Obando, Arnoldo | 2230 |  Colombia |
13 | |
| Obando, Carlos | 1974 |  Peru |
12 | |
| Obando, Richard | 2102 | Peru |
9 | |
| Obarcanin, Nijaz | 2008 | Bosnia And Herzegovina |
23 | |
| Obdrzalkova, Anita | 1963 |  Slovakia |
60 | |
| Obels, Jiri | 2042 |  Netherlands |
59 | |
| Obels, Pepijn | 1744 | Netherlands |
35 | |
| Obenaus, Thomas | 1746 |  Austria |
15 | |
| Oberbarnscheidt, Ludger | 2264 |  Germany |
52 | |
| Oberberger, Guenther | 1813 | Austria |
14 | |
| Oberbichler, Robert | 1924 | Austria |
8 | |
| Oberdorfer, Christof | 1754 | Austria |
9 | |
| Obere, Roman Franz | 1988 | Germany |
7 | |
| Oberfrank, Istvan | 2091 |  Hungary |
37 | |
| Oberhofer, Andre | 2273 | Germany |
73 | |
| Oberhofer, Cedric | 2141 | Germany |
7 | |
| Oberhofer, Max | 2187 | Germany |
108 | |
| Oberhofer, Peter | 1835 | Germany |
7 | |
| Oberholzer, Francois | 2061 | FM |  South Africa |
1 |
| Oberholzer, Rex | 1982 |  Namibia |
38 | |
| Oberlin, Cecile | 1656 |  France |
1 | |
| Obermair, Walter | 1873 | Austria |
22 | |
| Oberman, Hotimir | 1951 | Croatia |
12 | |
| Obermayr, Hermann | 2152 | Austria |
152 | |
| Oberndoerfer, Frank | 1969 | Germany |
60 | |
| Oberngruber, Thomas | 2107 | Austria |
10 | |
| Obernoeder, Thomas | 1748 | Germany |
15 | |
| Oberoi, Shelev | 1936 | United States |
1 | |
| Oberpriller, Josef | 1987 | Germany |
27 | |
| Oberrauch, Martin | 2185 |  Italy |
26 | |
| Obers, Frits | 2113 | Netherlands |
138 | |
| Obersnel, Jan | 1721 |  Slovenia |
9 | |
| Oberst, Janosch | 1856 | Germany |
7 | |
| Oberst, Thomas | 2263 | FM | Germany |
154 |
| Oberste, Norbert | 1751 | Germany |
83 | |
| Oberweis, Paul | 2032 |  Luxembourg |
32 | |
| Obgolts, Erik | 2334 | FM |  Russian Federation |
7 |
| Obiamiwe, Paul | 1914 |  Nigeria |
74 | |
| Obiedzinski, Pawel | 1838 |  Poland |
9 | |
| Obiedzinski, Piotr | 1843 | Poland |
5 | |
| Obierak, Wladyslaw | 2089 | Poland |
40 | |
| Obili, Abhishek | 2090 | United States |
5 | |
| Objois, Pierre Henri | 1720 | France |
4 | |
| Oblak, Marko | 1636 | Italy |
9 | |
| Oblamski, Vladimir | 2083 |  Belarus |
23 | |
| Oblin, Pierre | 1835 | France |
1 | |
| Oblitas, Carlomagno | 2413 | IM | Peru |
333 |
| Obodchuk, Andrei | 2336 | IM | Russian Federation |
379 |
| Oboladze, Luka | 2378 |  Georgia |
29 | |
| Obolenskikh, Dmitry | 2538 | IM | Russian Federation |
82 |
| Obolentseva, Alexandra | 2311 | WIM | Russian Federation |
49 |
| Obolonin, Filipp | 1873 |  Estonia |
2 | |
| Obon Temprano, Sergi | 2306 | FM |  Spain |
54 |
| Obon Zuniga, Francisco | 1816 | Spain |
19 | |
| Obona, Jan | 2212 | Slovakia |
72 | |
| Oborina, Elena | 2030 | Russian Federation |
11 | |
| Oborny, Lubor | 1919 |  Czech Republic |
3 | |
| Oboron, Georges | 2005 | Poland |
13 | |
| Obradovic, Alexandar | 2225 |  Serbia |
1 | |
| Obradovic, Blazimir | 2139 | FM | Serbia |
4 |
| Obradovic, Dragan | 2022 | Serbia |
36 | |
| Obradovic, Milan | 1523 |  Switzerland |
5 | |
| Obradovic, Momcilo | 1892 | Serbia |
3 | |
| Obradovic, Vasilije | 2107 | Serbia |
12 | |
| Obralic, Esad | 2331 | FM | Bosnia And Herzegovina |
13 |
| Obran, Harald | 2032 | Austria |
80 | |
| Obregon, Andres Carlos | 2514 | GM |  Argentina |
238 |
| Obregon Garcia, Roxangel | 2105 | WFM |  Cuba |
9 |
| Obregon Rivero, Juan | 2391 | FM | Cuba |
126 |
| Obreht, Slobodan | 1977 | Germany |
23 | |
| Obreja, Mihai | 1816 | Romania |
13 | |
| Obrezchikov, Mikhail | 1880 | Russian Federation |
10 | |
| Obrien, Matthew J | 2104 | United States |
4 | |
| Obringer, Jean Marc | 2074 | France |
24 | |
| Obrochta, Bogdan | 2073 | Poland |
19 | |
| Obrovac, Zvonko | 2153 | Canada |
7 | |
| Obrsal, Josef | 1504 | Czech Republic |
41 | |
| Obrusnik, Dawid | 1748 | Poland |
9 | |
| Obrusnik, Michal | 2277 | FM | Poland |
48 |
| Obrusnik, Pawel | 1599 | Poland |
8 | |
| Obsivac, Josef | 2290 | FM | Czech Republic |
410 |
| Obst, James | 2097 |  Australia |
92 | |
| Obst, Martin | 2021 | Germany |
28 | |
| Obuca, Bajro | 2066 | CM | Bosnia And Herzegovina |
24 |
| Obukhov, Alexander | 2344 | GM | Russian Federation |
533 |
| Obukhov, Sergeij | 2078 |  Ukraine |
11 | |
| Oburka, Vladislav | 1810 | Czech Republic |
8 | |
| Ocabo Vera, Pedro Aristides | 1792 | Spain |
9 | |
| Ocakacan, Deniz | 1650 |  Turkey |
9 | |
| Ocampo, Fermin | 1953 | Argentina |
1 | |
| Ocampo, Gisel | 1481 | Argentina |
5 | |
| Ocampo, Raul | 2315 | Argentina |
63 | |
| Ocampo Vargas, Raul | 2102 | IM |  Mexico |
124 |
| Ocampos, Ian | 2054 | Argentina |
21 | |
| Ocampos, Martin | 1703 |  Paraguay |
2 | |
| Ocana Lameiro, Oliver | 1995 | Spain |
2 | |
| Ocana Roca, Juan Jesus | 2145 | Spain |
33 | |
| Ocantos, Manuel | 2219 | Luxembourg |
68 | |
| Ocariz Gallego, Jesus | 1953 | Spain |
25 | |
| Occari, Maurizio | 2045 | Italy |
22 | |
| Occhipinti, Giuseppe | 1942 | Italy |
1 | |
| Occhipinti, Massimo | 1925 | Italy |
22 | |
| Ocejo, Leyla | 2061 | Cuba |
8 | |
| Ocelik, Vaclav | 1826 | Netherlands |
9 | |
| Ocepek, Martin | 2105 | Slovenia |
16 | |
| Ochelli, Francisco | 1753 | Paraguay |
24 | |
| Ochirbat, Lkhagvajamts | 1933 | CM |  Mongolia |
8 |
| Ochirova, Irina | 1487 | Russian Federation |
10 | |
| Ochkoos, Jura | 2203 | FM | Canada |
235 |
| Ochkov, Radoslav | 1862 |  |
32 | |
| Ochman, Tomas | 1836 | Czech Republic |
21 | |
| Ochmann, Denis | 1485 | Germany |
7 | |
| Ochmann, Reimund | 2009 | Germany |
49 | |
| Ochneva, Inga | 2114 | WFM | Russian Federation |
8 |
| Ochoa, Carl Victor | 2276 |  Philippines |
35 | |
| Ochoa, Ismael | 1805 |  Honduras |
5 | |
| Ochoa, Jason | 1819 | United States |
5 | |
| Ochoa, Matias | 1961 | Argentina |
25 | |
| Ochoa de la Rosa, Manuel Dario | 2417 | FM | Cuba |
34 |
| Ochodek, Mariusz | 1985 | Poland |
9 | |
| Ochonski, Piotr | 2160 | Poland |
36 | |
| Ochrana, Ladislav | 1948 | Slovakia |
46 | |
| Ochs, Holger | 2225 | Germany |
63 | |
| Ochsner, Bjorn Moller | 2469 | IM |  Denmark |
175 |
| Ochsner, Thomas | 2280 | Denmark |
335 | |
| Ochtman, Henk | 2111 | Netherlands |
27 | |
| Ociepka, Dominika | 1409 | Poland |
1 | |
| Ockay, Tomas | 2125 | Czech Republic |
48 | |
| Ockenfels, Karsten | 1694 | Germany |
7 | |
| Ocnarescu, Victor | 2164 | Romania |
81 | |
| Ocokoljic, Zoran | 2070 | Serbia |
19 | |
| Ocon Galilea, Francisco Jose | 1949 | Spain |
23 | |
| Oconnor, Derek | 2215 | United States |
4 | |
| Ocwieja, Piotr | 1703 | Poland |
4 | |
| Ocytko, Andrzej | 2155 | Poland |
86 | |
| Ocytko, Anna | 1967 | Poland |
19 | |
| Ocytko, Michal | 1124 | Poland |
9 | |
| Odachowski, Arthur | 2205 | Canada |
64 | |
| Odadzic, Zoran | 1850 | Serbia |
4 | |
| Odde, Eilif | 1971 |  Norway |
40 | |
| Odden, Jan Ove | 1515 | Norway |
27 | |
| Oddone, Cristhian | 2268 |  Uruguay |
28 | |
| Odeev, Handszar | 2415 | GM |  Turkmenistan |
465 |
| Odeeva, Larisa | 2198 | WFM | Turkmenistan |
14 |
| Odegaard, Per Chr | 1754 | Norway |
2 | |
| Odegov, Artem | 2266 | Russian Federation |
18 | |
| Odeh, Kenneth | 1932 | FM | Nigeria |
50 |
| Odehnal, Jaroslav | 1974 | Czech Republic |
13 | |
| Odehnal, Miroslav | 2226 | Czech Republic |
22 | |
| Oden, Edgar | 2008 | Germany |
22 | |
| Odendaal, Frederick | 2021 | South Africa |
35 | |
| Odendahl, Reiner | 2367 | FM | Germany |
324 |
| Odendahl, Steven M | 2420 | IM | United States |
95 |
| Odermatt, Klaus | 1827 | Switzerland |
14 | |
| Odermatt, Stefan | 2132 | Switzerland |
6 | |
| Odesskij, Ilia | 2429 | IM | Russian Federation |
125 |
| Odinaev, Timur | 2302 | FM | Russian Federation |
9 |
| Odinaeva, Saodat | 1893 |  Tajikistan |
20 | |
| Odink, Karel | 2116 | Netherlands |
10 | |
| Odinokov, Nikolai | 2312 | Russian Federation |
82 | |
| Odisharia, Teona | 2178 | Georgia |
78 | |
| Odler, Daniel | 2067 | Slovakia |
84 | |
| Odnorozhenko, Evgenyi | 2289 | IM | Ukraine |
101 |
| Odnorozhenko, Kateryna | 2110 | WIM | Ukraine |
148 |
| Odor, Istvan | 2147 | Hungary |
1 | |
| Odunaiya, Victor | 1870 | United Kingdom |
4 | |
| Odzak, Senad | 1834 | Bosnia And Herzegovina |
2 | |
| Oe, Oluf | 1928 | Denmark |
24 | |
| Oechler, Hans Erich | 2121 | Germany |
24 | |
| Oechslein, Rainer | 2228 | Germany |
228 | |
| Oehler, Markus | 2063 | Germany |
35 | |
| Oehlerich, Per | 1939 | Denmark |
22 | |
| Oehlmann, Dieter | 2041 | Germany |
48 | |
| Oehmichen, Jan | 1863 | Denmark |
24 | |
| Oehne, Ingo | 1804 | Germany |
7 | |
| Oehne, Timo | 2116 | Germany |
11 | |
| Oehrlein, Alexander | 2144 | Germany |
29 | |
| Oehrlein, Thomas | 2232 | Germany |
91 |
| Name | ELO | Title | Federation | Games |
| Oei, Hway Ik | 2071 | Netherlands |
195 | |
| Oelert, Ralf | 1981 | Germany |
50 | |
| Oellrich, Torben | 1665 | Germany |
15 | |
| Oelrichs, Manfred | 1667 | Germany |
155 | |
| Oelze, Joern | 1971 | Germany |
48 | |
| Oendy, Oscar | 2081 | Australia |
30 | |
| Oepen, Lothar | 2064 | Germany |
79 | |
| Oergel, Ullrich | 1954 | Germany |
14 | |
| Oertel, David | 1979 | Germany |
27 | |
| Oertel, Thomas | 1999 | Germany |
29 | |
| Oesch, Harry | 1941 | Switzerland |
5 | |
| Oest, Thorsten | 2111 | Germany |
36 | |
| Oesterle, Peter | 2385 | Germany |
79 | |
| Oesterreicher, Moritz | 1803 | Austria |
6 | |
| Oettel, Andreas | 2244 | Germany |
32 | |
| Oettel, Lothar | 1945 | Germany |
25 | |
| Oettinger, Hagen | 2111 | Germany |
72 | |
| Oetzel, Roland | 2270 | Germany |
23 | |
| Oez, Edda | 1517 | Germany |
60 | |
| Oezen, Alf | 1911 | Germany |
13 | |
| Ofak, Marko | 2029 | Slovenia |
11 | |
| Ofek, Ram | 2112 |  Israel |
43 | |
| Offermann, Fernando | 2143 | Germany |
39 | |
| Officer, Amy | 1825 | WFM | Scotland |
71 |
| Offinger, Robert | 2181 | Germany |
96 | |
| Offringa, Joost | 2297 | Netherlands |
50 | |
| Offringa, Tjaart Jan | 2070 | Netherlands |
57 | |
| Ofir, Eran | 2112 | Israel |
1 | |
| Ofitserian, Boris | 2411 | FM | Russian Federation |
82 |
| Ofner, Maximilian | 2174 | Austria |
12 | |
| Ofstad, Per | 2064 | Norway |
369 | |
| Ofstad, Sigurd | 2012 | Norway |
2 | |
| Ogaard, Leif | 2386 | GM | Norway |
588 |
| Ogada Osir, Ibrahim | 2123 | Australia |
18 | |
| Ogando Gonzalez, Francisco J | 1951 | Spain |
4 | |
| Oganessian, Gaguik | 2002 | FM |  Armenia |
2 |
| Oganessiats, Ernest | 2260 | Armenia |
11 | |
| Oganezova, Tamila | 2057 | Russian Federation |
46 | |
| Oganian, Arsen | 2228 | Russian Federation |
11 | |
| Oganian, Miran | 2432 | IM | Russian Federation |
204 |
| Oganian, Roman | 2215 | Russian Federation |
12 | |
| Oganisjn, Roman | 2275 | Russian Federation |
107 | |
| Oganyan, Arsen | 2224 | Russian Federation |
21 | |
| Ogden, Marcus W | 1735 | Australia |
3 | |
| Ogdon, Ricardo | 1612 | Paraguay |
25 | |
| Oger, Claude | 1939 | France |
85 | |
| Oger, Daniel | 1882 |  Belgium |
21 | |
| Oger, Philippe | 1821 | France |
1 | |
| Oges, Helene | 1699 | France |
28 | |
| Oggier, Cesar | 2225 | Argentina |
13 | |
| Ogiewka, Rafal | 2065 | Poland |
11 | |
| Oginski, Ulrich | 1798 | Germany |
9 | |
| Oglaza, Oskar | 2344 | FM | Poland |
45 |
| Ogleznev, Alexandr | 2328 | FM |  Moldova |
115 |
| Oglobilia, Alexander | 2242 | Ukraine |
65 | |
| Ogloblin, Nikolay | 2346 | IM | Russian Federation |
150 |
| Ogloblina, Lidiya | 2146 | Russian Federation |
9 | |
| Ognean, Mihnea-Ionut | 2278 | FM | Romania |
28 |
| Ognerubova, Anastasia | 2052 | WFM | Russian Federation |
17 |
| Ognibene, Piero | 1770 | Italy |
2 | |
| Ognjacevic, Alen | 1956 | Croatia |
18 | |
| Ognjan, Renato | 2075 | Croatia |
7 | |
| Ogonowska, Katarzyna | 1849 | Poland |
77 | |
| Ogorodov, Petr | 1808 | Russian Federation |
15 | |
| Ograbek, Grzegorz | 2137 | Poland |
19 | |
| Ogradi, Gregor | 1958 | Slovenia |
16 | |
| Ogunshola, Ben | 2143 | Nigeria |
30 | |
| Ogunwobi, Tolulope | 2164 | Nigeria |
6 | |
| Oguz, Huseyin | 1754 | Turkey |
6 | |
| Oguzov, Shamil | 2196 | Russian Federation |
9 | |
| Oharek, Vlastimil | 1764 | Czech Republic |
2 | |
| Ohat, Imre | 1941 | Hungary |
1 | |
| Ohayv, Nikolaj | 1935 | Denmark |
8 | |
| Ohl, Christophe | 2107 | France |
15 | |
| Ohlund, Nicolas | 1972 | France |
8 | |
| Ohlzon, Nils Johan | 2158 |  Sweden |
84 | |
| Ohman, Anders | 2046 | Sweden |
28 | |
| Ohme, Kerstin | 1753 | Germany |
18 | |
| Ohnesorg, Felix | 1837 | Germany |
11 | |
| Ohnmacht, Rolf | 1862 | Germany |
13 | |
| Ohnmacht, Simon | 1883 | Germany |
52 | |
| Ohresser, Olivier | 1868 | France |
4 | |
| Ohrn, Stellan | 1981 | Sweden |
9 | |
| Ohst, Holger | 1919 | Germany |
36 | |
| Ohunov, Bobur | 2151 |  Uzbekistan |
9 | |
| Oillic, Goulven | 1736 | France |
1 | |
| Oitzl, Danijel | 1816 | Austria |
12 | |
| Ojagverdiyev, Zaur | 2043 |  Azerbaijan |
15 | |
| Ojala, Hannu | 1782 |  Finland |
19 | |
| Ojanen, Jyrki | 2059 | Finland |
40 | |
| Ojanen, Pekka | 2225 | Finland |
32 | |
| Ojaos Penalver, Abel | 1981 | Spain |
18 | |
| Ojas Kulkarni | 2226 |  India |
40 | |
| Ojeda, Hector | 2117 |  Chile |
12 | |
| Ojeda, Hernan | 2173 | Argentina |
92 | |
| Ojeda, Javier | 2197 | Paraguay |
22 | |
| Ojeda, Jesus David | 2128 | Colombia |
9 | |
| Ojeda Ruiz, Jose Luis | 1601 | Spain |
37 | |
| Ojer Lora, Iker | 2074 | Spain |
30 | |
| Ojo, Damilola | 2041 | Nigeria |
0 | |
| Ojrzynski, Blazej | 2120 | Poland |
12 | |
| Ojstosek, Mirko | 1719 | Germany |
31 | |
| Okamura, Milton Kasuo | 2067 |  Brazil |
81 | |
| Okanli, Muratcan | 1635 | Turkey |
1 | |
| Okanovic, Jasmina | 1647 | Croatia |
21 | |
| Okara, Andrey | 2340 | IM | Russian Federation |
123 |
| Okay, Arda Efe | 1885 | Turkey |
6 | |
| Okay, Koray | 2076 | Turkey |
7 | |
| Okcular, Ayhan | 2145 | Turkey |
31 | |
| Oker, Bertil | 1589 | Germany |
7 | |
| Okhotnik, Vladimir | 2384 | GM | France |
1127 |
| Okhrimenko, Sergei | 2209 | Ukraine |
9 | |
| Okicic, Nermin | 2195 | Bosnia And Herzegovina |
14 | |
| Okike, David | 2160 | Nigeria |
82 | |
| Okilj, Nevenko | 2136 | Serbia |
7 | |
| Okilj, Tigran | 2097 | Serbia |
2 | |
| Okkes, Menno | 2321 | FM | Netherlands |
196 |
| Okladnikov, Gennady | 2067 | Russian Federation |
59 | |
| Okon, Dariusz | 2194 | Poland |
2 | |
| Okoniewski, Pawel | 1775 | Poland |
9 | |
| Okorn, Jan | 1768 | Slovenia |
9 | |
| Okorn, Nejc | 1837 | Slovenia |
18 | |
| Okos, Alexander | 2055 | Slovakia |
77 | |
| Okosieme, Iozeph | 2020 | United Kingdom |
36 | |
| Okoth, Joachim | 2171 |  Uganda |
56 | |
| Okpu, Robert | 1724 | Sweden |
7 | |
| Okrajek, Alexander | 2224 | Germany |
137 | |
| Okrosa, Marijan | 2036 | Croatia |
58 | |
| Okrouhlik, Zdenek | 1819 | Czech Republic |
9 | |
| Okruashvili, Georgy | 2118 | Russian Federation |
10 | |
| Okrucinski, Tadeusz | 2182 | FM | Poland |
40 |
| Okrugic, Tomislav | 1893 | Croatia |
14 | |
| Okrugin, Alexander | 2018 | Russian Federation |
8 | |
| Okrugin, Sergey | 2334 | IM | Russian Federation |
193 |
| Oksa, Jaakko | 2046 | Finland |
17 | |
| Oksanen, Timo | 1943 | Finland |
66 | |
| Oksnevad, Arild | 1804 | Norway |
3 | |
| Oksuz, Akin | 2167 | Turkey |
8 | |
| Okulov, Andrey | 2251 | Russian Federation |
9 | |
| Okuma, Yutaka | 1499 | Brazil |
3 | |
| Okumus, Gorkem Deniz | 1875 | Turkey |
21 | |
| Okun, Evgeny | 2163 | Russian Federation |
55 | |
| Okun, Leonid | 2266 | FM | Russian Federation |
52 |
| Okunev, Lev | 2214 | Russian Federation |
38 | |
| Okunev, Taras | 2107 | Russian Federation |
21 | |
| Okuniewski, Boguslaw | 2217 | Poland |
33 | |
| Okur, Kadir | 1844 | Turkey |
1 | |
| Okus, Melih | 2080 | Turkey |
14 | |
| Okuyaz, Duru | 2139 | WFM | Turkey |
27 |
| Olabe Odriozola, Eduardo | 1912 | Spain |
19 | |
| Olaciregui, Eduardo | 1999 | Argentina |
19 | |
| Olafsson, Arni | 1331 |  Iceland |
5 | |
| Olafsson, David | 2267 | FM | Iceland |
126 |
| Olafsson, Fridrik | 2355 | GM | Iceland |
1042 |
| Olafsson, Helgi | 2510 | GM | Iceland |
1335 |
| Olafsson, Smari | 1944 | Iceland |
2 | |
| Olah, Janos | 1951 | Hungary |
27 | |
| Olah, Jozsef | 1872 | Hungary |
15 | |
| Olah, Peter | 2201 | Hungary |
7 | |
| Olah, Sandor | 1989 | Hungary |
165 | |
| Olah, Zsigmond | 2087 | Hungary |
59 | |
| Olaizola Ortega, Luis | 2130 | Spain |
165 | |
| Olander, Aleksi | 2047 | Finland |
15 | |
| Olape, Bunmi | 2252 | IM | Nigeria |
87 |
| Olar, Adrian | 1809 | Romania |
5 | |
| Olarasu, Gabriela | 2256 | WGM | Romania |
689 |
| Olarasu, Ioana | 1769 | Romania |
12 | |
| Olarasu, Iuliana | 2058 | Romania |
5 | |
| Olariu, Luca-Stefan | 2019 | Romania |
8 | |
| Olaru, Daniel | 2081 | France |
4 | |
| Olatunji, Oluwatobiloba | 1918 | WFM | Nigeria |
11 |
| Olausson, Claes Goran | 2274 | Sweden |
87 | |
| Olave Parra, Hugo | 1785 | Chile |
17 | |
| Olay, Edgar Reggie | 2268 | Philippines |
40 | |
| Olay Valdes, Rodrigo | 1834 | Spain |
94 | |
| Olaya, Noemi | 1550 |  Ecuador |
8 | |
| Olaya, Sandra | 1669 | Ecuador |
7 | |
| Olazarri, Marcelo | 2208 | Uruguay |
86 | |
| Olbrich, Jakob | 1946 | Germany |
7 | |
| Olbrich, Joachim | 2150 | FM | Germany |
114 |
| Olbrich, Marina | 2330 | WIM | Germany |
305 |
| Olbrich, Peter | 1951 | Germany |
15 | |
| Olbrig, Michael | 1853 | Germany |
18 | |
| Olbrisch, Manfred | 2109 | Germany |
61 | |
| Olcayoz, Alper | 2244 | FM | Turkey |
227 |
| Olcum, Ahmet | 2316 | CM | Turkey |
25 |
| Old, Stefan | 1526 | Germany |
5 | |
| Oldach, Ehrenfried | 2021 | Germany |
163 | |
| Olde, Hendrik | 2325 | FM | Estonia |
69 |
| Olde, Henning | 1839 | Germany |
9 | |
| Olde, Margareth | 2110 | WFM | Estonia |
12 |
| Oldenhuis, Lance | 2002 | Netherlands |
48 | |
| Oldernes, Lars Arne | 1537 | Norway |
44 | |
| Oldigs, Adolf | 1653 | Germany |
21 | |
| Olea Perez, Mario | 2263 | FM | Spain |
289 |
| Olear, Laszlo | 2072 | Hungary |
35 | |
| Olebile, Thato | 2136 | FM | Botswana |
10 |
| Oledzki, Adam | 1801 | Poland |
20 | |
| Oledzki, Tomasz | 2030 | Poland |
23 | |
| Oleinik, Alexander | 2111 | Russian Federation |
10 |