| Fighter | Record | Last Bout |
|---|---|---|
| Jon Delos Reyes | 8-5-0 | 2015-10-24 |
| Jordan Radev | 23-5-0 | 2007-12-29 |
| Jordan Rinaldi | 14-7-0 | 2019-03-16 |
| Jorge Rivera | 20-9-0 | 2012-01-20 |
| Josh Rafferty | 9-8-0 | 2005-04-09 |
| Juancamilo Ronderos | 4-2-0 | 2023-02-18 |
| Karl Roberson | 9-6-0 | 2022-07-09 |
| Keith Rockel | 12-4-1 | 2003-11-21 |
| Kenny Robertson | 15-5-0 | 2016-09-17 |
| Kevin Randleman | 17-16-0 | 2002-01-11 |
| Kevin Rosier | 2-6-0 | 1994-12-16 |
| Kleydson Rodrigues | 8-4-0 | 2024-05-18 |
| Kristian Rothaermel | 4-3-0 | 2006-06-28 |
| Leigh Remedios | 18-10-2 | 2002-07-13 |
| Loik Radzhabov | 18-6-1 | 2024-07-20 |
| Luis Ramos | 20-10-2 | 2012-06-22 |
| Luke Rockhold | 16-6-0 | 2022-08-20 |
| Manuel Rodriguez | 11-5-0 | 2012-12-14 |
| Mara Romero Borella | 12-9-0 (2 NC) | 2020-09-19 |
| Marcelo Rojo | 16-10-0 | 2022-12-03 |
| Marco Polo Reyes | 8-7-0 | 2019-09-21 |
| Marco Ruas | 9-4-2 | 1999-07-16 |
| Marcos Rogerio de Lima | 22-10-1 | 2024-02-17 |
| 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 |
| Matthew Riddle | 8-3-0 (2 NC) | 2013-02-16 |
| Mauricio Rua | 27-14-1 | 2023-01-21 |
| 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 |
| Montana De La Rosa | 13-9-1 | 2024-06-08 |
| Nick Ring | 14-4-0 | 2013-12-06 |
| Nick Roehrick | 7-1-0 | 2017-07-07 |
| 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 |
| Rachael Ostovich | 4-6-0 | 2020-11-28 |
| 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 Natal | 21-9-1 | 2017-07-22 |
| Rafaello Oliveira | 17-8-0 | 2014-02-22 |
| Rainy Martinez | 0-2-0 | 1997-02-07 |
| Ramazan Emeev | 20-6-0 | 2022-06-11 |
| Rameau Thierry Sokoudjou | 18-18-0 | 2008-10-18 |