Tenis Ö ile başlayan oyuncular
- Orlando City
- Östersunds FK
- O Agwi, M/O'Hoisin
- Oceanne Lopez
- Olga Danilova
- Ola Abou Zekry/Ellie Blackford
- Olga Danilova/Jane Dunyon
- Oleksandra Oliynykova/Daria Yesypchuk
- Oksana Selekhmeteva
- Ola Abou Zekry
- Önnereds HK
- Oklahoma City Thunder
- Oleksandra Oliynykova/Anastasiya Zaparyniuk
- Ola Abou Zekry/Lamis Alhussein Abdel Aziz
- Omar Brigida/Giuseppe Tresca
- Ofek Shimanov/Ben Weintraub
- Oskar Grzegorzewski/Lasse Poertner
- Oh My God
- OpTic Gaming
- OpTic Texas
- Odorizzi/Turati
- Oskar Grzegorzewski/Borys Zgola
- Olga Danilova/Prisha Vyas
- Osgar O'Hoisin/Henrik Wiersholm
- Olga Golas
- Ospreys
- Oliver Bekker
- Oliver Crawford
- Oetzbach/Slump
- Ovcharenko/Tsygourova
- Ohunene Comfort Yakubu
- Oleg Kolninov/Alexander Krylov
- Oskarshamns AIK
- Oliwia Orlinska
- Oliver Sanchez/Cherny
- Oradini/Serafini
- Oleksandra Oliynykova/Mariya Poduraeva
- Oliver Moratalla/Pohjola
- Obradovic/Radjenovic
- Oakland Athletics
- Orix Buffaloes
- Oklahoma City Dodgers
- Ohashi Remika
- Oleksandr Usyk
- Oliveira/Popko
- Obradovic/Tadic
- Omae/Sato
- Oliveira/Portugal
- Oliver Jevtovic
- Olivia Gadecki/Olivia Nicholls