| Fighter | Record | Last Bout |
|---|---|---|
| Aaron Simpson | 12-5-0 | 2012-10-05 |
| Adrian Serrano | 56-29-4 | 2000-06-09 |
| Adriano Santos | 0-1-0 | 1998-10-16 |
| Alessio Sakara | 19-11-0 (2 NC) | 2013-10-26 |
| Alex Da Silva | 21-4-0 | 2022-06-04 |
| Alex Schoenauer | 15-10-0 | 2005-04-09 |
| Alex Soto | 8-3-1 | 2012-05-15 |
| Alex Stiebling | 19-11-1 (1 NC) | 2000-11-17 |
| Aljamain Sterling | 26-5-0 | 2026-04-25 |
| Amar Suloev | 24-7-0 | 2002-05-10 |
| Amir Sadollah | 6-5-0 | 2014-09-20 |
| Anderson Dos Santos | 21-9-0 | 2021-08-07 |
| Anderson Silva | 34-11-0 (1 NC) | 2020-10-31 |
| Andre Soukhamthath | 13-8-0 | 2019-08-31 |
| Andreas Stahl | 10-4-0 | 2015-12-10 |
| Andrei Semenov | 34-9-2 | 2002-05-10 |
| Andrew Sanchez | 13-7-0 | 2021-10-16 |
| Anthony Smith | 38-22-0 | 2025-04-26 |
| Antonina Shevchenko | 10-4-0 | 2022-07-09 |
| Antonio Dos Santos | 6-4-0 | 2015-06-20 |
| Antonio Silva | 19-12-1 | 2016-09-24 |
| Ariane da Silva | 17-11-0 | 2025-06-07 |
| Assuerio Silva | 16-8-0 (1 NC) | 2007-04-21 |
| Augusto Sakai | 16-5-1 | 2023-02-25 |
| Austin Springer | 12-4-0 | 2020-08-29 |
| Axel Sola | 13-1-1 | 2026-09-05 |
| Baisangur Susurkaev | 12-0-0 | 2026-05-09 |
| Ben Saunders | 22-13-2 | 2019-12-14 |
| Ben Sosoli | 7-3-0 (2 NC) | 2020-02-22 |
| Benardo Sopaj | 13-3-0 | 2026-10-03 |
| Benoit Saint Denis | 17-4-0 (1 NC) | 2026-07-11 |
| Bentley Syler | 5-1-0 | 2015-03-21 |
| Bobby Southworth | 10-6-0 (1 NC) | 2005-04-09 |
| Boston Salmon | 6-3-0 | 2019-10-18 |
| Brad Scott | 11-6-0 | 2018-05-27 |
| Braxton Smith | 5-2-0 | 2023-05-06 |
| Brendan Schaub | 10-5-0 | 2014-12-06 |
| Brian Stann | 12-6-0 | 2013-03-02 |
| Bruno Santos | 15-2-0 | 2014-10-04 |
| Bruno Silva | 15-9-2 (1 NC) | 2026-06-06 |
| Bruno Silva | 23-13-0 | 2025-05-10 |
| Bruno Souza | 10-3-0 | 2022-03-26 |
| Cameron Saaiman | 9-3-0 | 2025-04-26 |
| Cameron Smotherman | 12-7-0 | 2026-05-30 |
| Chael Sonnen | 29-15-1 | 2013-11-16 |
| Chan Sung Jung | 17-8-0 | 2023-08-26 |
| Chas Skelly | 19-3-0 (1 NC) | 2022-02-19 |
| Chase Sherman | 16-12-0 | 2023-05-13 |
| Chris Sanford | 5-1-0 | 2005-04-09 |
| Chris Saunders | 16-8-0 | 2012-06-01 |