| Fighter | Record | Last Bout |
|---|---|---|
| Jonathan Micallef | 10-1-0 | 2026-05-02 |
| Jordan Mein | 31-12-0 | 2018-07-28 |
| Jorge Masvidal | 35-17-0 | 2023-04-08 |
| Jose Daniel Medina | 11-7-0 | 2026-02-28 |
| Jose Maria | 37-7-0 (2 NC) | 2013-11-09 |
| Jose Montanha | 7-1-0 | 2026-08-08 |
| Joseph Morales | 15-2-0 | 2026-09-12 |
| Josias Musasa | 8-2-0 | 2025-09-27 |
| Juan Manuel Puig | 11-4-0 | 2014-11-22 |
| Julian Marquez | 9-6-0 | 2025-03-01 |
| Juliana Miller | 6-4-0 | 2026-08-08 |
| Justin Martin | 4-3-0 | 1997-02-07 |
| Justin McCully | 11-5-2 | 2009-08-29 |
| Kanako Murata | 12-3-0 | 2023-10-07 |
| Keith Mielke | 0-5-0 | 1996-02-16 |
| Khalid Murtazaliev | 14-2-0 | 2018-09-15 |
| Kris McCray | 8-5-0 | 2011-03-26 |
| Kris Moutinho | 14-8-0 | 2026-02-28 |
| Kristof Midoux | 6-10-0 | 2006-08-17 |
| Lauren Mueller | 5-3-0 | 2019-10-12 |
| Lauren Murphy | 16-7-0 | 2025-07-12 |
| Lee Murray | 8-2-1 (1 NC) | 2004-01-31 |
| Leonardo Mafra | 13-4-0 | 2015-07-18 |
| Leonardo Morales | 6-2-0 | 2015-06-06 |
| Lerone Murphy | 17-1-1 | 2026-03-21 |
| Levan Makashvili | 15-2-1 | 2016-01-30 |
| Lucas Martins | 19-3-0 | 2016-04-10 |
| Lyoto Machida | 24-8-0 | 2018-05-12 |
| Mac Danzig | 21-12-1 | 2013-12-14 |
| Maciej Jewtuszko | 12-3-0 | 2011-02-26 |
| Mackens Semerzier | 8-4-0 (1 NC) | 2012-03-02 |
| Mackenzie Dern | 17-5-0 | 2026-08-15 |
| Macy Chiasson | 11-6-0 | 2026-02-28 |
| Mads Burnell | 9-3-0 | 2018-05-27 |
| Magnus Cedenblad | 14-5-0 | 2016-11-19 |
| Magomed Ankalaev | 22-2-1 (1 NC) | 2026-07-25 |
| Magomed Bibulatov | 14-2-0 | 2019-02-02 |
| Magomed Gadzhiyasulov | 9-1-0 | 2025-01-11 |
| Magomed Mustafaev | 14-4-0 | 2020-02-22 |
| Magomed Tuchalov | 7-0-0 | 2026-07-25 |
| Magomed Zaynukov | 9-0-0 | 2026-07-25 |
| Maheshate | 12-5-0 | 2025-08-23 |
| Maia Stevenson | 6-5-0 | 2018-02-03 |
| Maiquel Falcao | 37-10-0 (1 NC) | 2010-11-20 |
| Mairbek Taisumov | 27-6-0 | 2019-09-07 |
| Mairon Santos | 18-1-0 | 2025-12-06 |
| Makhmud Muradov | 26-8-0 (1 NC) | 2024-02-03 |
| Maki Pitolo | 13-9-0 | 2021-12-04 |
| Makwan Amirkhani | 17-9-0 | 2023-03-18 |
| Malcolm Gordon | 14-8-0 | 2024-01-20 |