Player
Obafemi Martins
Position: forwardNationality: Nigeria
Player
Obed Vargas
Position: midfielderNationality: Spain, United States, Mexico
Player
Ogenyi Onazi
Position: midfielderNationality: Nigeria
Player
Oguchi Onyewu
Position: centre-back, defenderNationality: United States
Player
Oka Nikolov
Position: goalkeeperNationality: North Macedonia
Player
Ola Kamara
Position: forwardNationality: Sierra Leone, Norway
Player
Olivier Mbaizo
Position: defenderNationality: Cameroon
Player
Omar Bravo
Position: forwardNationality: Mexico
Player
Omar Caetano
Position: midfielderNationality: Uruguay
Player
Omar Gaber
Position: midfielder, defenderNationality: Egypt
Player
Omar Gonzalez
Position: defenderNationality: United States
Player
Onandi Lowe
Position: sweeper, forwardNationality: Jamaica
Player
Ondřej Lingr
Position: forwardNationality: Czech Republic
Player
Oniel Fisher
Position: defenderNationality: Jamaica
Player
Onyekachi Apam
Position: defenderNationality: Nigeria
Player
Oriol Rosell
Position: midfielderNationality: Spain
Player
Oscar Damiani
Position: forwardNationality: Italy
Player
Osinachi Ohale
Position: defenderNationality: Nigeria
Player
Osvaldo Alonso
Position: midfielderNationality: Cuba, United States
Player
Osvaldo Ardiles
Position: midfielderNationality: Argentina
Player
Ousmane Dabo
Position: defensive midfielderNationality: Senegal, France
Player
Owen Otasowie
Position: midfielderNationality: United States
Player
Óscar Murillo
Position: centre-backNationality: Colombia