| Or, Hasidim | Israel U17 |  Israel | Delantero |
| Orachev, Miki | Bulgaria U17 |  Bulgaria | Centrocampista |
| Orav, Maria | Estonia WU17 |  Estonia | Defensa |
| Orbaiz, Pablo | Rubin (RUS) |  España | Centrocampista |
| Ordasi, Gergő | Hungary U17 |  Hungría | Portero |
| Ordega, Francisca | Rossiyanka (RUS) |  Nigeria | Delantero |
| Ordets, Ivan | Illychivets (UKR) / Ukraine U21 |  Ucrania | Defensa |
| Öreg, Cintia Mónika | Hungary WU17 | Hungría | Delantero |
| Oremo, Johan | Gefle (SWE) |  Suecia | Delantero |
| Orestes | Veria (GRE) |  Brasil | Defensa |
| Orhan, Ak | Elazığspor (TUR) |  Turquía | Defensa |
| Orhan, Belma | Sarajevo (BIH) / Bosnia and Herzegovina WU19 |  Bosnia-Herzegovina | Defensa |
| Orhan Gülle | Gaziantepspor (TUR) / Turkey U21 | Turquía | Centrocampista |
| Orhan Şam | Fenerbahçe (TUR) | Turquía | Defensa |
| Origi, Divock | LOSC (FRA) / Belgium U19 |  Bélgica | Centrocampista |
| Orikhovskiy, Pavlo | Ukraine U17 | Ucrania | Centrocampista |
| Oriol, Eduardo | Zaragoza (ESP) | España | Delantero |
| Oriol Romeu | Chelsea (ENG) / Spain U21 | España | Centrocampista |
| Orkan Çinar | Turkey U17 | Turquía | Centrocampista |
| Orkun Uşak | Mersin (TUR) | Turquía | Portero |
| Orlinov, Marin | Bulgaria U19 | Bulgaria | Portero |
| Orlov, Jakob | Gefle (SWE) | Suecia | Delantero |
| Orlova , Valentina | Russia WOCO |  Rusia | Defensa |
| Ørntoft, Christina | Malmö (SWE) / Denmark WOCO |  Dinamarca | Defensa |
| Oroş, Cristian | Rapid Bucureşti (ROU) |  Rumanía | Defensa |
| Orosa, Cristhian | Andorra U21 |  Andorra | Defensa |
| Orozco, Yohandry | Wolfsburg (GER) |  Venezuela | |
| Orozco, Daniel | Asteras (GRE) | España | Defensa |
| Oršić, Mislav | Inter Zaprešić (CRO) / Croatia U21 |  Croacia | Delantero |
| Oršula, Filip | Wigan (ENG) / Slovakia U21 |  Eslovaquia | Centrocampista |
| Ortega Salinas, Jorge Miguel | Legia (POL) |  Paraguay | Centrocampista |
| Ortega-Jurado, Alina | Germany WU17 |  Alemania | Delantero |
| Ortiz | Interviú (ESP) / Spain FUT | España | Defensa |
| Ortiz, Laura | Spain WU19 | España | Delantero |
| Ortiz, Celso | AZ (NED) | Paraguay | Centrocampista |
| Ortlechner, Manuel | Austria Wien (AUT) / Austria |  Austria | Defensa |
| Örün, Erdinc | Hamburg (GER) | Alemania | Delantero |
| Osaj, Leutrim | Nafta (SVN) / Albania U21 |  Albania | Centrocampista |
| Osanga, King | Sochaux (FRA) | Nigeria | Centrocampista |
| Osborn, Grant | England FUT |  Inglaterra | Delantero |
| Osborn, Ben | England U19 | Inglaterra | Centrocampista |
| Osbourne, Isaac | Aberdeen (SCO) | Inglaterra | Centrocampista |
| Oscar | Chelsea (ENG) | Brasil | Centrocampista |
| Óscar Cardozo | Benfica (POR) | Paraguay | Delantero |
| Óscar González | Valladolid (ESP) | España | Centrocampista |
| Oscar Neira | Encamp (AND) / Andorra FUT | Andorra | Delantero |
| Ose, Ilze | Skonto (LVA) |  Letonia | Centrocampista |
| Ose, Camilla | Røa (NOR) / Norway WU17 |  Noruega | Delantero |
| Osei, Kevin | Marseille (FRA) |  Francia | Centrocampista |
| O'Shaughnessy, Daniel | Finland U19 |  Finlandia | Defensa |
