Tous les combattants
 | Oleg Borisov | 2-1-0 REC | #2717 |  |
 | Oleg Dadonov | 1-1-0 REC | #2137 | |
 | Oleg Nagorny | 0-1-0 REC | #7597 |  |
 | Oleg Olenichev | 0-1-0 REC | #5933 | |
 | Oleg Popov | 7-1-0 REC | #1186 | |
 | Oleg Sanakoev | 0-1-0 REC | #7662 | |
 | Oleg Taktarov | 6-2-1 UFC | #1854 | |
 | Oļegs Jemeļjanovs | 0-2-0 REC | #6228 |  |
 | Oleksandr Moisa | 2-1-0 REC | #1340 | |
 | Oleksii Polischuck | 4-4-0 REC | #1861 | |
 | Olena Kolesnyk | 4-4-0 REC | #3396 | |
 | Olendet Apouassa Romeo | 0-1-0 REC | #5687 |  |
 | Olga Rubin | 4-3-0 REC | #2295 | |
 | Oli Thompson | 0-2-0 UFC | #5215 |  |
 | Oliver Enkamp | 0-2-0 UFC | #3839 |  |
 | Oliver Tero | 1-1-0 REC | #2182 | |
 | Olivia Hendrickson | 1-0-0 REC | #5064 |  |
 | Olivia Parker | 0-1-0 REC | #5268 | |
 | Olivier Aubin-Mercier | 7-5-0 UFC | #198 |  |
 | Olivier Fleurmon | 1-0-0 REC | #2231 |  |
 | Olivier Murad | 1-0-0 REC | #5610 |  |
 | Olli Santalahti | 2-3-0 REC | #3564 |  |
 | Ollie Sarwa | 5-1-0 REC | #562 | |
 | Ollie Schmid | 0-1-0 UFC | #3087 |  |
 | Olutobi Kalejaiye | 1-1-0 REC | #1792 |  |