| Fighter | Record | Last Bout |
|---|---|---|
| Murilo Bustamante | 15-8-1 | 2002-05-10 |
| Murtazali Magomedov | 11-0-0 | 2026-06-20 |
| Muslim Salikhov | 22-6-0 | 2026-09-12 |
| Myktybek Orolbai | 16-3-1 | 2026-08-15 |
| Myles Jury | 17-4-0 | 2019-02-17 |
| Nate Maness | 16-3-0 | 2024-06-15 |
| Nate Marquardt | 35-19-2 | 2017-11-11 |
| Nate Mohr | 9-7-0 | 2009-01-17 |
| Nazareno Malegarie | 28-4-0 | 2015-09-05 |
| Neil Magny | 32-15-0 | 2026-08-15 |
| Nicco Montano | 5-3-0 | 2019-07-13 |
| Nicholas Musoke | 13-5-0 (1 NC) | 2017-05-28 |
| Nick Maximov | 8-2-0 | 2022-10-15 |
| Nikolas Motta | 15-6-0 (1 NC) | 2025-06-21 |
| Nina Milosevic | 9-1-0 | 2026-08-01 |
| Omar Morales | 11-4-0 | 2023-03-18 |
| Pat Miletich | 29-7-2 | 2002-03-22 |
| Patchy Mix | 20-3-0 | 2025-10-04 |
| Pedro Munhoz | 20-10-0 (2 NC) | 2024-11-02 |
| Peggy Morgan | 4-4-0 | 2013-11-30 |
| Phillip Miller | 16-0-0 | 2002-11-22 |
| Quinn Mulhern | 18-4-0 | 2014-01-04 |
| Rainy Martinez | 0-2-0 | 1997-02-07 |
| Randa Markos | 11-12-1 | 2021-10-23 |
| Rashid Magomedov | 20-2-0 | 2017-04-15 |
| Renato Moicano | 21-7-1 | 2026-09-19 |
| Reza Madadi | 14-6-0 | 2017-05-28 |
| Rhys McKee | 14-7-1 | 2025-09-06 |
| Richardson Moreira | 7-4-0 | 2015-01-31 |
| Richie Miranda | 13-2-0 | 2026-08-08 |
| Rob MacDonald | 5-4-0 | 2006-08-26 |
| Robert McDaniel | 28-10-0 | 2014-03-15 |
| Roman Mitichyan | 8-3-0 | 2008-04-02 |
| Ronny Markes | 17-5-0 | 2014-03-23 |
| Roque Martinez | 15-8-2 | 2021-06-19 |
| Rory MacDonald | 19-4-0 | 2016-06-18 |
| Rory Markham | 17-6-0 | 2010-03-27 |
| Roxanne Modafferi | 25-21-0 | 2022-02-12 |
| Rudyard Moncayo | 0-3-0 | 1995-07-14 |
| Ruslan Magomedov | 14-1-0 | 2015-10-03 |
| Ryan MacDonald | 10-2-0 | 2019-09-14 |
| Ryan Madigan | 5-3-0 | 2009-03-07 |
| Ryan McGillivray | 12-0-1 | 2011-06-04 |
| Sabina Mazo | 9-4-0 | 2022-03-12 |
| Sammy Morgan | 18-12-0 | 2006-08-17 |
| Sara McMann | 13-6-0 | 2022-03-26 |
| Sarah Moras | 6-8-0 | 2021-01-16 |
| Scott Morris | 2-1-0 | 1994-03-11 |
| Sean McCorkle | 17-7-0 | 2011-03-26 |
| Sergey Morozov | 19-5-0 | 2022-12-17 |