| Nationality | Name | Wins | Losses |
|---|---|---|---|
| Nationality | Name | Wins | Losses |
| Dutch Congolese | Chris Ngimbi | 50 | 22 |
| French | Hamza Ngoto | 50 | 1 |
| Japanese | Takahito Niimi | 14 | 8 |
| French | Stéphane Nikiéma | 79 | 17 |
| Chinese | Wei Ninghui | 41 | 17 |
| Japanese | Masaaki Noiri | 48 | 11 |
| American | K. J. Noons | 12 | 2 |
| Thai | Samingdet Nor.Anuwatgym | 48 | 21 |
| South African | Jan Nortje | 9 | 16 |
| Lithuanian | Arnold Oborotov | 43 | 13 |
| Swedish | Marcus Öberg | 27 | 7 |
| American | Shane Oblonsky | 12 | 5 |
| Swiss | Volkan Oezdemir | 5 | 0 |
| Japanese | Eisaku Ogasawara | 45 | 8 |
| Japanese | Takaya Ogura | 18 | 11 |
| Japanese | Tatsuya Oiwa | 23 | 9 |
| Japanese | Ryuya Okuwaki | 25 | 6 |
| Ukrainian | Alexander Oleinik | 44 | 7 |
| Brazilian | Jonatan Oliveira | 33 | 13 |
| Nigerian | Andy Ologun | 2 | 6 |