Football Équipes commençant par O
- Once Caldas Manizales U20
- Oureskolernes BK
- Orlando City SC (W)
- Ostavalls IF
- Okocimski KS Brzesko
- Oakville Blue Devils
- OKC Energy FC (W)
- Orsomarso SC U20
- OTP (W)
- Orlando Pirates FC (Reserves)
- Oakleigh Cannons U21
- Olympic Kingsway SC U20
- Oulunsalon Pallo
- Old Bridge FC
- Olympic FC (W)
- OFK Topličanin Prokuplje
- One Knoxville SC
- Once Deportivo de Ahuachapan
- OFK Vrsac
- Oakland Stompers
- Olympia FC Warriors Reserves
- Ol Berytus (W)
- Olympiacos FC B
- Once Deportivo de Ahuachapan Reserves
- Olimpia (W)
- Operario Ferroviario EC U20
- OFK Levski 2007
- Olympique Saumur FC
- Ormeau U23
- OFC Lokomotiv Mezdra
- Olympique Saint-Quentin
- O'Higgins (Wom)
- OFK Pirin Blagoevgrad (W)
- Oddar Meanchey
- Orlęta Aleksandrów Kujawski
- Olimp Gościno
- Orgullo Surtam
- Oceanía FC
- Olimpia Asunción U19
- Olympique de Valence
- Olympic Star Muyinga FC
- Ol Beirutus (W)
- Ostrovia 1909 Ostrow Wielkopolski (W)
- OM Saidham
- Olympique Magrane
- Olympique Magrane U21
- Östersunds Ik
- Oklahoma State Cowboys
- Oklahoma Sooners
- Oregon State Beavers