| Fighter | Record | Last Bout |
|---|---|---|
| Marcos Rogerio de Lima | 22-10-1 | 2024-02-17 |
| Marina Rodriguez | 17-6-2 | 2025-05-03 |
| Marion Reneau | 9-8-1 | 2021-07-17 |
| Mark De La Rosa | 11-5-0 | 2020-06-13 |
| Mark Robinson | 1-0-0 (1 NC) | 2001-02-23 |
| Marwan Rahiki | 9-0-0 | 2026-09-12 |
| Mateusz Rebecki | 21-5-0 | 2026-08-01 |
| Matthew Riddle | 8-3-0 (2 NC) | 2013-02-16 |
| Mauricio Rua | 27-14-1 | 2023-01-21 |
| Mauricio Ruffy | 14-2-0 | 2026-09-19 |
| Max Rohskopf | 5-1-0 | 2020-06-20 |
| Mike Rhodes | 10-5-0 | 2014-12-20 |
| Mike Ricci | 11-5-0 | 2013-09-21 |
| Mike Rio | 10-5-0 | 2014-01-25 |
| Mike Rodriguez | 11-7-0 (1 NC) | 2021-09-18 |
| Mike Russow | 15-3-0 (1 NC) | 2013-01-26 |
| Mitch Ramirez | 8-4-0 | 2026-07-18 |
| Mitch Raposo | 11-3-0 | 2026-06-20 |
| Montana De La Rosa | 13-9-1 | 2024-06-08 |
| Montse Rendon | 7-2-0 | 2026-03-14 |
| Montserrat Conejo Ruiz | 10-5-0 | 2025-11-01 |
| Nick Ring | 14-4-0 | 2013-12-06 |
| Nick Roehrick | 7-1-0 | 2017-07-07 |
| Nilson Rojas | 9-1-0 | 2026-08-29 |
| Nursulton Ruziboev | 37-10-2 (2 NC) | 2026-09-05 |
| Paul Redmond | 12-7-0 | 2015-07-18 |
| Paul Rodriguez | 10-9-2 | 2001-06-29 |
| Pedro Rizzo | 20-11-0 | 2003-11-21 |
| Pete Rodriguez | 5-2-0 | 2024-02-03 |
| Phil Rowe | 11-7-0 | 2026-02-21 |
| Piera Rodriguez | 12-2-0 | 2026-03-14 |
| RJ Harris | 6-0-0 | 2026-07-18 |
| Rachael Ostovich | 4-6-0 | 2020-11-28 |
| Rafa Garcia | 19-4-0 | 2026-09-12 |
| Rafael Alves | 20-12-0 | 2023-02-25 |
| Rafael Carino | 2-1-1 | 1996-05-17 |
| Rafael Cavalcante | 12-7-0 (1 NC) | 2016-02-06 |
| Rafael Cerqueira | 11-4-0 | 2025-11-22 |
| Rafael Dos Anjos | 32-17-0 | 2026-10-03 |
| Rafael Estevam | 14-1-0 | 2026-04-04 |
| Rafael Fiziev | 14-5-0 | 2026-06-27 |
| Rafael Natal | 21-9-1 | 2017-07-22 |
| Rafael Tobias | 14-3-0 | 2026-08-15 |
| Rafaello Oliveira | 17-8-0 | 2014-02-22 |
| Rainy Martinez | 0-2-0 | 1997-02-07 |
| Ramazan Emeev | 20-6-0 | 2022-06-11 |
| Ramazan Temirov | 20-3-0 | 2026-10-24 |
| Rameau Thierry Sokoudjou | 18-18-0 | 2008-10-18 |
| Ramiro Hernandez | 19-9-0 | 2014-01-25 |
| Ramiz Brahimaj | 13-7-0 | 2026-08-15 |