| Oakley, Aaron | Swindon (ENG) / Wales U19 |  Gales | Defensa |
| Oancea, Evgheni | Moldova U17 |  Moldavia | Centrocampista |
| Oar, Tomas | Utrecht (NED) |  Australia | Delantero |
| Obadă, Cristian | Moldova FUT | Moldavia | Delantero |
| Obadeyi, Tope | Rio Ave (POR) |  Inglaterra | Delantero |
| Obasi, Chinedu | Schalke (GER) |  Nigeria | Delantero |
| Obayomi, Ibrahim | Marítimo (POR) | Nigeria | |
| Obeng, Curtis | Swansea (WAL) | Inglaterra | Defensa |
| Oberemko, Andriy | Metalurh Zaporizhya (UKR) |  Ucrania | Centrocampista |
| Oberhauser, David | Ajaccio (FRA) |  Francia | Centrocampista |
| Oberressl, Carmen | Austria WU19 |  Austria | Defensa |
| Obertan, Gabriel | Newcastle (ENG) | Francia | Centrocampista |
| Oberweis, Marc | Luxembourg |  Luxemburgo | Portero |
| Obi, Joel | Internazionale (ITA) | Nigeria | Centrocampista |
| Obiang, Pedro Mba | Sampdoria (ITA) / Spain U21 |  España | Centrocampista |
| Obin, Jérémy | Valenciennes (FRA) | Francia | Defensa |
| Obinna, Victor | Lokomotiv Moskva (RUS) | Nigeria | Delantero |
| Obita, Jordan | Reading (ENG) | Inglaterra | Centrocampista |
| Oblak, Jan | Rio Ave (POR) / Slovenia / Slovenia U21 |  Eslovenia | Portero |
| Obradović, Milan | Arsenal Kyiv (UKR) |  Serbia | Defensa |
| Obradović, Ivan | Zaragoza (ESP) | Serbia | Defensa |
| Obraniak, Ludovic | Bordeaux (FRA) / Poland |  Polonia | Delantero |
| O'Brien, Michelle | Republic of Ireland WOCO |  República de Irlanda | Delantero |
| O'Brien, Joey | West Ham (ENG) / Republic of Ireland | República de Irlanda | Centrocampista |
| Occean, Olivier | Eintracht Frankfurt (GER) |  Canadá | Delantero |
| Ochoa, Guillermo | Ajaccio (FRA) |  México | Portero |
| Ochoa, Ane | Spain WU19 | España | Portero |
| Ochs, Patrick | Hoffenheim (GER) |  Alemania | Defensa |
| O'Connell, Ciara | Republic of Ireland WU19 | República de Irlanda | Centrocampista |
| O'Connell, Jack | York (ENG) / England U19 | Inglaterra | Defensa |
| O'Connor, Amy | Republic of Ireland WU17 | República de Irlanda | Centrocampista |
| Oczipka, Bastian | Eintracht Frankfurt (GER) | Alemania | Defensa |
| O'Dea, Darren | Celtic (SCO) / Republic of Ireland | República de Irlanda | Defensa |
| Odebrecht, Viola | Wolfsburg (GER) / Germany WOCO | Alemania | Centrocampista |
| Ødegård, Magnar | Norway U21 |  Noruega | Defensa |
| Odehnalová, Adéla | Czech Republic WOCO |  República Checa | Centrocampista |
| Odelius, Kim | Brommapojkarna (SWE) |  Suecia | |
| Odemwingie, Peter | West Brom (ENG) | Nigeria | Delantero |
| Odeurs, Justien | Belgium WU17 |  Bélgica | Portero |
| Odibe, Michael | Arsenal Kyiv (UKR) | Nigeria | Defensa |
| Ódinsdóttir, Gudný Björk | Kristianstads (SWE) / Iceland WOCO |  Islandia | Centrocampista |
| Odjidja, Vadis | Club Brugge (BEL) | Bélgica | Centrocampista |
| Odoi, Denis | Anderlecht (BEL) | Bélgica | Defensa |
| Odonkor, David | Hoverla (UKR) | Alemania | Delantero |
| O'Donnell, Stephen | Dundee (SCO) |  Escocia | |
| O'Donnell, Hayley | Northern Ireland WU19 |  Irlanda del Norte | Centrocampista |
| Odysseos, Odysseas | Omonia (CYP) / Cyprus FUT |  Chipre | Portero |
| Oehri, Yves | Vaduz (LIE) / Liechtenstein |  Liechtenstein | Centrocampista |
| Oehri, Marco | Liechtenstein U17 | Liechtenstein | Defensa |
| Oehrl, Torsten | Augsburg (GER) | Alemania | Delantero |
