Tennis Giocatori che iniziano con O
- Olivia Carneiro
- Oleksandra Oliynykova/Anastasiya Konstantinova Soboleva
- Olivia Lincer
- Ottavia Massetti
- Oziera Ahmad
- Olivia Carneiro/Imogen Haddad
- Ofek Shimanov
- Oskar Grzegorzewski
- Oskar Oliver Stuchlik
- Oskar Grzegorzewski/Adam Majchrzak
- Ondrej Horak
- Olympiacos Piraeus VB
- Obras Sanitarias
- Oxford United
- Oxford City
- Oldham Athletic
- OH Leuven
- Orlando Pirates Reserves
- Ourense CF
- Orense SC
- Oskar Grzegorzewski/Maxim Zhukov
- Oscar Galimardanov
- Oliver Ojakaar
- Olivia Bergler/Defne Cirpanli
- OK BRION Challengers
- O Beloborodko, I/Krutykh
- Oleg Prihodko
- Orlando Magic
- O Lechemia, E/Nicholls
- Orel Kimhi/Ofek Shimanov
- Oana Georgeta Simion/Joelle Lilly Sophie Steur
- Offaly
- Orleans