| Fighter | Record | Last Bout |
|---|---|---|
| Nina Milosevic | 9-1-0 | 2026-08-01 |
| Nina Nunes | 11-7-0 | 2022-08-13 |
| Nissen Osterneck | 12-4-0 | 2009-04-01 |
| Noad Lahat | 11-2-0 | 2016-02-06 |
| Noah Gugnon | 10-2-0 | 2026-08-01 |
| Noe Hernandez | 5-5-0 | 1998-05-15 |
| Nohelin Hernandez | 9-4-0 | 2019-09-28 |
| Nolan Ticman | 4-3-0 | 2015-05-16 |
| Nora Cornolle | 10-4-0 | 2026-09-05 |
| Nordine Taleb | 15-7-0 | 2019-09-07 |
| Norifumi Yamamoto | 18-6-0 (2 NC) | 2015-02-28 |
| Norma Dumont | 13-3-0 | 2026-09-26 |
| Norman Parke | 23-6-1 | 2016-02-27 |
| Nursulton Ruziboev | 37-10-2 (2 NC) | 2026-09-05 |
| Nurullo Aliev | 12-0-0 | 2026-10-24 |
| Nyamjargal Tumendemberel | 10-1-0 | 2026-03-07 |
| Oban Elliott | 12-5-0 | 2026-08-01 |
| Ode Osbourne | 13-9-0 (2 NC) | 2026-02-21 |
| Oleg Taktarov | 17-5-2 | 1995-12-16 |
| Oli Thompson | 17-10-0 | 2012-08-04 |
| Oliver Enkamp | 7-2-0 | 2018-03-17 |
| Olivier Aubin-Mercier | 11-5-0 | 2019-07-27 |
| Ollie Schmid | 4-3-0 | 2026-05-02 |
| Oluwale Bamgbose | 6-4-0 | 2017-12-16 |
| Omar Morales | 11-4-0 | 2023-03-18 |
| Omari Akhmedov | 21-6-1 | 2021-07-10 |
| Onassis Parungao | 2-1-0 | 1995-09-08 |
| Orion Cosce | 8-2-0 | 2023-05-20 |
| Orlando Wiet | 1-5-0 | 1994-03-11 |
| Oskar Piechota | 11-3-1 (1 NC) | 2020-06-20 |
| Otari Tanzilovi | 10-2-0 | 2026-06-20 |
| Ottman Azaitar | 13-3-0 | 2024-12-14 |
| Oumar Sy | 12-3-0 | 2026-09-05 |
| Ovince Saint Preux | 27-18-0 | 2024-10-05 |
| Ozzy Diaz | 10-4-0 | 2026-09-19 |
| Pablo Garza | 12-4-0 | 2013-04-06 |
| Paddy Holohan | 12-2-1 | 2015-10-24 |
| Paddy Pimblett | 24-4-0 | 2026-07-11 |
| Paige VanZant | 8-5-0 | 2020-07-11 |
| Pannie Kianzad | 17-9-0 | 2024-08-10 |
| Papy Abedi | 10-4-0 | 2013-08-28 |
| Parker Porter | 14-9-0 | 2023-08-26 |
| Pascal Krauss | 11-2-0 | 2013-08-31 |
| Pat Audinwood | 11-2-1 | 2010-12-11 |
| Pat Barry | 8-7-0 | 2013-12-06 |
| Pat Healy | 34-23-0 (1 NC) | 2014-07-16 |
| Pat Miletich | 29-7-2 | 2002-03-22 |
| Pat Sabatini | 22-5-0 | 2026-05-09 |
| Pat Schilling | 5-2-0 | 2012-06-01 |
| Patchy Mix | 20-3-0 | 2025-10-04 |