2020 Zomer Olympische Spelen - Atleten
| Atleet | Sport |
|---|---|
 José Leyver Ojeda | Athletiek |
 Emmanuel Ojeli | Athletiek |
 Keiju Okada | Zeilen |
| Naoya Okada | Schieten |
| Kumiko Okada | Athletiek |
| Blessing Okagbare | Athletiek |
| Misugu Okamoto | Skateboarden |
| Chidi Okezie | |
| Patience Okon | Athletiek |
 Lawrence Okoye | Athletiek |
 Maria Olarasu | Canoe/Kayak |
| Dan Olaru | Boogschieten |
 Raluca Olaru | Tennis |
 Anna Olasz | Aquatics |
 Keet Oldenbeuving | Skateboarden |
 Penelope Oleksiak | Aquatics |
 Peeter Olesk | Schieten |
 Facundo Olezza | Zeilen |
| Andrés Olivas | Athletiek |
 Larissa Oliveira | Aquatics |
 Nélson Oliveira | Wielrennen |
| Ingrid Oliveira | Aquatics |
| Fernanda Oliveira Horn | Zeilen |
 Javianne Oliver | Athletiek |
| Mayan Oliver | Moderne Vijfkamp |