| Fighter | Record | Last Bout |
|---|---|---|
| Aaron Riley | 30-14-1 | 2013-07-27 |
| Aaron Rosa | 18-6-0 | 2012-03-02 |
| Alex Reyes | 13-5-0 | 2024-08-17 |
| Alex Ricci | 10-5-0 | 2017-02-19 |
| Alvin Robinson | 15-9-0 | 2008-11-15 |
| Andre Roberts | 14-2-1 | 1999-07-16 |
| Anthony Rocco Martin | 17-6-0 | 2020-06-06 |
| Antonio Rodrigo Nogueira | 34-10-1 (1 NC) | 2015-08-01 |
| Bas Rutten | 28-4-1 | 1999-05-07 |
| Bec Rawlings | 7-8-0 | 2018-04-07 |
| Ben Rothwell | 39-14-0 | 2021-11-13 |
| Benji Radach | 21-7-0 (1 NC) | 2002-09-27 |
| Brad Riddell | 10-4-0 | 2022-11-12 |
| Buddy Roberts | 12-3-0 | 2012-08-11 |
| Carlos Eduardo Rocha | 9-4-0 | 2012-06-08 |
| Chad Reiner | 33-18-0 | 2007-06-12 |
| Chance Rencountre | 14-4-0 | 2019-11-02 |
| Charles Rosa | 14-8-0 | 2022-07-23 |
| Chris de la Rocha | 5-3-0 | 2018-12-15 |
| Claudio Ribeiro | 11-5-0 | 2024-03-02 |
| Colin Robinson | 10-12-0 | 2008-01-19 |
| Daniel Roberts | 15-7-0 | 2012-01-20 |
| Danny Roberts | 18-8-0 | 2023-07-22 |
| Dante Rivera | 16-7-0 | 2008-06-21 |
| Davi Ramos | 10-4-0 | 2020-07-18 |
| David Roberts | 5-8-0 | 1999-05-07 |
| Diego Rivas | 10-2-0 | 2018-05-19 |
| Drako Rodriguez | 7-3-0 | 2021-08-07 |
| Eddie Ruiz | 1-1-0 | 2003-06-06 |
| Francisco Rivera | 11-7-0 (1 NC) | 2016-07-30 |
| Gabe Ruediger | 18-8-0 | 2011-02-05 |
| George Roop | 15-13-1 | 2015-09-26 |
| Germaine de Randamie | 10-5-0 | 2024-04-06 |
| Gideon Ray | 17-15-1 | 2006-11-11 |
| Goran Reljic | 15-8-0 | 2010-11-13 |
| Hector Ramirez | 10-6-1 | 2007-06-16 |
| Irwin Rivera | 10-6-0 | 2020-09-19 |
| Jake Rosholt | 12-5-0 (1 NC) | 2009-11-21 |
| Jared Rollins | 8-4-0 | 2007-12-08 |
| Jared Rosholt | 14-4-0 | 2016-02-06 |
| Jason Reinhardt | 20-3-0 | 2011-08-14 |
| Jerome Rivera | 10-6-0 | 2021-07-10 |
| Jesse Ronson | 21-12-0 (1 NC) | 2022-10-01 |
| Jessica Rakoczy | 1-5-0 (1 NC) | 2015-04-25 |
| Jimmie Rivera | 23-5-0 | 2021-02-27 |
| Joao Roque | 7-2-4 | 2000-06-09 |
| Joe Riggs | 44-17-0 (1 NC) | 2016-02-21 |
| Joey Roberts | 4-3-0 | 1999-03-05 |
| Johnny Rees | 13-5-0 (1 NC) | 2008-12-10 |
| Johnny Rhodes | 2-1-0 | 1994-03-11 |