| Fighter | Record | Last Bout |
|---|---|---|
| Rudyard Moncayo | 0-3-0 | 1995-07-14 |
| Ruslan Magomedov | 14-1-0 | 2015-10-03 |
| Russell Doane | 15-8-0 | 2018-02-24 |
| Rustam Khabilov | 24-4-0 | 2019-11-09 |
| Ryan Bader | 23-5-0 | 2016-11-19 |
| Ryan Benoit | 10-8-0 | 2021-07-31 |
| Ryan Couture | 11-5-0 | 2013-08-31 |
| Ryan Hall | 9-2-0 | 2021-12-11 |
| Ryan Janes | 10-3-0 | 2017-12-01 |
| Ryan Jensen | 21-8-0 | 2011-04-30 |
| Ryan Jimmo | 19-5-0 | 2015-05-30 |
| Ryan LaFlare | 14-3-0 | 2018-10-06 |
| Ryan MacDonald | 10-2-0 | 2019-09-14 |
| Ryan Madigan | 5-3-0 | 2009-03-07 |
| Ryan McGillivray | 12-0-1 | 2011-06-04 |
| Ryan Parker | 0-1-0 | 1995-09-08 |
| Ryan Roberts | 21-12-1 (1 NC) | 2008-04-02 |
| Ryan Thomas | 20-8-0 | 2008-11-15 |
| Ryo Chonan | 22-13-0 | 2009-04-18 |
| Sabah Homasi | 11-8-0 | 2018-01-20 |
| Sabina Mazo | 9-4-0 | 2022-03-12 |
| Saeed Hosseini | 0-1-0 | 1997-05-30 |
| Sage Northcutt | 11-2-0 | 2018-07-14 |
| Sai Wang | 20-6-1 | 2014-08-23 |
| Saidyokub Kakhramonov | 10-3-0 | 2022-12-17 |
| Sako Chivitchian | 8-1-0 | 2010-12-04 |
| Salim Touahri | 10-4-0 | 2019-08-03 |
| Sam Adkins | 7-20-2 | 1996-09-20 |
| Sam Alvey | 33-18-1 (1 NC) | 2022-08-06 |
| Sam Fulton | 0-2-0 | 1997-07-27 |
| Sam Hoger | 10-4-0 | 2007-02-03 |
| Sam Sicilia | 15-8-0 | 2017-02-19 |
| Sam Stout | 20-12-1 | 2015-08-23 |
| Sammy Morgan | 18-12-0 | 2006-08-17 |
| Samy Schiavo | 10-6-0 | 2008-10-18 |
| Sanae Kikuta | 31-9-3 (1 NC) | 2000-04-14 |
| Saparbeg Safarov | 9-3-0 | 2020-03-07 |
| Sara McMann | 13-6-0 | 2022-03-26 |
| Sarah Alpar | 9-6-0 | 2021-09-18 |
| Sarah Frota | 9-2-0 | 2019-07-27 |
| Sarah Kaufman | 18-4-0 (1 NC) | 2015-12-19 |
| Sarah Moras | 6-8-0 | 2021-01-16 |
| Sasha Palatnikov | 6-4-0 | 2021-08-21 |
| Satoshi Honma | 4-6-3 | 2000-04-14 |
| Scott Adams | 8-1-0 | 2000-03-10 |
| Scott Askham | 14-4-0 | 2017-03-18 |
| Scott Baker | 1-1-0 | 1994-03-11 |
| Scott Bessac | 4-6-0 | 1995-12-16 |
| Scott Ferrozzo | 4-2-0 | 1997-02-07 |
| Scott Fiedler | 0-1-0 | 1996-07-12 |