| Fighter | Record | Last Bout |
|---|---|---|
| Richard Crunkilton | 19-4-0 | 2003-04-25 |
| Richard Walsh | 9-5-0 | 2016-11-26 |
| Richardson Moreira | 7-4-0 | 2015-01-31 |
| Richie Hightower | 8-4-0 (1 NC) | 2007-12-08 |
| Richie Miranda | 13-2-0 | 2026-08-08 |
| Richie Smullen | 3-1-1 | 2018-07-06 |
| Richie Vaculik | 10-4-0 | 2015-11-14 |
| Rick Davis | 3-1-1 | 2006-05-27 |
| Rick Story | 19-9-0 | 2016-08-20 |
| Ricky Glenn | 22-9-2 | 2024-08-17 |
| Ricky Rainey | 12-6-0 | 2018-11-30 |
| Ricky Simon | 22-7-1 | 2026-09-26 |
| Ricky Turcios | 13-6-0 | 2026-03-07 |
| Riki Fukuda | 24-9-0 (1 NC) | 2013-03-02 |
| Rin Nakai | 19-2-1 | 2016-03-19 |
| Rinat Fakhretdinov | 24-1-1 | 2025-09-06 |
| Rinya Nakamura | 10-1-0 | 2026-09-26 |
| Rizvan Kuniev | 14-3-1 (1 NC) | 2026-10-24 |
| Roan Carneiro | 21-11-0 | 2017-02-11 |
| Rob Broughton | 16-7-1 | 2011-11-05 |
| Rob Emerson | 18-12-0 (1 NC) | 2010-03-31 |
| Rob Font | 22-10-0 | 2026-03-07 |
| Rob Kimmons | 25-9-0 | 2011-03-03 |
| Rob MacDonald | 5-4-0 | 2006-08-26 |
| Rob Wilkinson | 11-2-0 | 2018-02-10 |
| Rob Yundt | 9-5-0 | 2008-06-21 |
| Robbie Lawler | 30-16-0 (1 NC) | 2023-07-08 |
| Robelis Despaigne | 5-2-0 | 2026-09-19 |
| Robert Bryczek | 18-7-0 | 2026-09-26 |
| Robert Drysdale | 7-0-0 (1 NC) | 2014-07-06 |
| Robert Lucarelli | 0-1-0 | 1994-03-11 |
| Robert McDaniel | 28-10-0 | 2014-03-15 |
| Robert Peralta | 18-8-0 (1 NC) | 2015-04-04 |
| Robert Ruchala | 11-3-0 | 2026-04-04 |
| Robert Sanchez | 8-2-0 | 2018-09-08 |
| Robert Valentin | 13-6-0 (1 NC) | 2026-08-01 |
| Robert Whiteford | 14-4-0 | 2016-04-10 |
| Robert Whittaker | 28-9-0 | 2026-07-11 |
| Roberto Romero | 8-5-1 | 2025-04-26 |
| Roberto Soldic | 21-4-0 | 2026-10-03 |
| Roberto Traven | 6-4-1 | 2001-11-02 |
| Rocky Lee | 3-2-0 | 2015-04-11 |
| Rodney Wallace | 26-15-1 | 2010-08-07 |
| Rodolfo Bellato | 13-3-1 (1 NC) | 2026-09-26 |
| Rodolfo Rubio Perez | 10-16-1 | 2014-11-08 |
| Rodolfo Vieira | 11-5-0 | 2026-09-26 |
| Rodrigo Damm | 13-9-0 | 2015-01-03 |
| Rodrigo Nascimento | 11-3-0 (1 NC) | 2024-11-02 |
| Rodrigo Ruas | 4-5-1 (1 NC) | 2002-06-22 |
| Rodrigo Sezinando | 9-2-0 | 2025-09-13 |