Calcio Squadre che iniziano con Ö
- OTP (W)
- Orlando Pirates FC (Reserves)
- Oakleigh Cannons U21
- Olympic Kingsway SC U20
- Oulunsalon Pallo
- Old Bridge FC
- Olympic FC (W)
- OFK Topličanin Prokuplje
- OFK Dynamo Malzenice
- Orapa United FC
- Olympic FC U23
- OFK Mladost DG
- OFC Zagorets Nova Zagora
- Otterup B and IK
- Olympique Akbou
- Old Bridge FC U23
- OL Reign (W)
- Os TF U19
- Omiya Ardija (W)
- O'Connor Knights FC U23
- OFK Brzi Brod
- Oxley United FC U23
- Olympique Ales
- Oakland County FC
- Once Deportivo de Ahuachapan
- OFK Vrsac
- Oakland Stompers
- Olympia FC Warriors Reserves
- Okinawa SV
- Oud-Heverlee Leuven B
- Ol Berytus (W)
- Olympiacos FC B
- Oslo FA Dakar
- Once Deportivo de Ahuachapan Reserves
- O Elvas CAD
- Oviedo Moderno CF B (W)
- Ossett United FC
- Oral Roberts Golden Eagles (W)
- Orvietana Calcio
- Orgryte IS (W)
- Onisillos Sotiras FC
- Oviedo Moderno CF (W)
- Obra Kościan
- Orlęta Aleksandrów Kujawski
- Olimp Gościno
- Oceanía FC
- Olimpia Asunción U19
- 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
- Ohio State Buckeyes
- Ole Miss Rebels
- Oregon Ducks
- Ohio State Buckeyes Women
- Ole Miss Rebels (W)
- Oklahoma City Thunder
- Olympiada Lympion
- Omonia Psevda
- Orestis Orestiadas
- OFI Crete FC (Wom)