| Id | Name | Points | Country | Skill level | Bidding systems | Remarks/Recommended of |
|---|---|---|---|---|---|---|
| oatokerud | Ole Andreas Tokerud | Norway | expert | Natural | Pia | |
| o_brisa | Juvenal | Portugal | expert | SAYC | ||
| obaron | Manuel | 21 | Germany | expert | SEF | chicken |
| oblio11 | Sorin | Canada | advanced+ | SAYC | ||
| obscura | Liam Ofe | 6 | Ireland | expert | 2/1 | voile7 |
| ochinko | Petko Boukov | 9 | Bulgaria | advanced | SAYC | |
| ocirne1 | Enrico Salerno | Italy | advanced | naturale, 5aMaggiore, Q40 | 000bridge7 | |
| octandre | Léon | Panama | expert | fifth major | Pia | |
| odyssea | DDr. Ingrid Propst | 5 | Austria | advanced+ | sayc and owb | vanilla |
| Oetzi 06 | Henning Bern | 1 | Germany | advanced++ | Forum d + SEF | Herfried Franzi Beppina |
| ofraa | Ofra | Israel | advanced++ | SAYC | ||
| ogdiva | Eileen Malabre | Australia | advanced+ | SAYC | Pia | |
| ogelby | Johan A. Holmgren | 7 | Finland | intermediate++ | natural with mods | |
| Oguzcan_81 | Ismail | 36 | Türkiye | advanced++ | SAYC | Pia |
| ohoaha | India | intermediate | SAYC | mauwev | ||
| Oily | 1 | India | purshi | |||
| okaragulle | Orhan | Türkiye | advanced++ | SAYC | standart card. | |
| okarstein |
Ole Karstein |
13 | Norway | advanced+ | SAYC | agnetha2 |
| oksay-4 | Serdar | Türkiye | expert | 5 maj | 11romeo | |
| okvince * | Vincent | 5 | Australia | expert | Pia | |
| oladaniel | Ola Danielsen | Norway | advanced+ | SAYC | Pia | |
| olafem | Olaf Emmler | 4 | Germany | expert++ | forum D+ | hanne0811 |
| OLD_SCHATE | Trifon | 172 | Bulgaria | expert | sayc, natural | dguf |
| Old1chris | Christy McKenzie | 7 | USA | advanced+ | SAYC | Rikke |
| oldgalot12 | Richard | 16 | USA | expert | ||
| Ole N | Ole Nørmølle | Denmark | expert | SAYC | ||
| Ole1 | Ole | 4 | Denmark | intermediate | SAYC | 5-card major |
| olegario | 22 | advanced | Pia | |||
| olekt1 | 7 | Norway | advanced | SAYC | Pia | |
| olimpica00 * | Isabel | 19 | Spain | expert | 2/1 | |
| olipop_24 | Olimpiu | Portugal | advanced+ | SAYC | tori_60 | |
| oll | Oliver Loper | 3 | Estonia | expert | SAYC, 2/1, precision | junior |
| olstro | Trond Olsen | Norway | expert | near SAYC | Pia | |
| oltitzas | Oltita | 13 | Romania | advanced+ | SAYC | |
| omorfos | Orhan | 5 | Türkiye | advanced+ | SAYC | ZEYNEP33 |
| omrgen | Omry | Israel | advanced | SAYC | ogdiva | |
| onecabbie | Richard Howard | USA | expert | SAYC | Wckedkadie | |
| onesmile4u | Ana | Romania | advanced | SAYC | Pia | |
| only1chris | 13 | 14 | England | advanced | SAYC and Acol | |
| onur33 | Veysel Gundogdu | Turkey | advanced++ | SAYC | Pia | |
| onutdaniel | Onut | 109 | Romania | expert | SAYC | garbisro |
| ooescu | Diane Turkin | USA | advanced | 2/1 | jdhilts | |
| oouu | Lami | 27 | China | advanced++ | 2/1 | |
| opera2006 | Ileana Poenaru | 6 | Romania | advanced++ | SAYC | yky22 |
| orchestra | Antionette | Canada | advanced+ | SAYC | Pia | |
| orlowski | Adrian Orlowski | 1 | Poland | intermediate | SAYC, wj2000 | rychp40 |
| oryon2 | Alex | Romania | advanced | |||
| osman 1 | Osman | Türkiye | expert | SAYC, 2/1 | Pia | |
| Osman_45 | Osman | 9 | Türkiye | expert | SAYC, 2/1 | stefany555 |
| osy38tr | Osman | 1 | Türkiye | expert | 5 card major | |
| ostap1 | Aleksander | 5 | Estonia | expert | natural, strong club, precision | |
| 0strugurel | George | Australia | advanced++ | SAYC | Pia | |
| Otard | Steinar Hoff | Norway | advanced | 5c maj, better Minor | elisa95 | |
| otsu | Ottar Sundt | Norway | advanced | SAYC | Pia | |
| otto40 | Harald Haugstad | 15 | Norway | intermediate++ | 5 cards major | |
| ouragan1 | Anne Cordonnie | 17 | France | advanced | SEF | gryn 010606 |
| OVA |
Angelov Ognyan |
105 | Bulgaria |
advanced++ |
Precision |
|
| ovho | Ovidiu | Romania | expert | Precision | ||
| ovicor | Ovidiu | 5 | Romania | expert | strong club, SAYC, major in 5 | Pia |
| ovidiul | Dorian Ovidiu | 29 | Romania | expert | 5 maj | suceava4 |
| Ovyx278 | Ovidiu | 8 | Romania | advanced | SAYC full | |
| outline | Guadeloupe | advanced | SEF | Pia | ||
| owlhouse | Maria Caalder | 3 | Germany | intermediate | SAYC or Forum D | Pia |
| oylc | Oylc | 7 | China | expert | precision | Pia |
| oystein | Oystein | Norway | expert | SAYC | Pia | |
| ozalp | Alaattin Ozalp | Türkiye | advanced | iemetergin | ||
| ozbal | Yalcin Ozbal | Türkiye | expert | SAYC | bobh2 | |
| oziris | 4 | Bulgaria | expert | SAYC or Precision | ||
| ozlem68 | Ozlem | Türkiye | advanced+ | 2/1 | ant07 | |
| ozoz257 | Ozlem | Türkiye | advanced | 2/1 | cleanup | |
| ozswell1 | Australia | advanced | SAYC | lisdee2 | ||
| ozver | Halit | 7 | Türkiye | expert | SAYC or 2/1 | Yigitsuna |