| Fighter | Record | Last Bout |
|---|---|---|
| Steve Montgomery | 9-5-0 | 2015-11-14 |
| Steve Nelmark | 2-1-0 | 1996-12-07 |
| Steve Steinbeiss | 9-4-0 | 2010-08-01 |
| Steve Vigneault | 12-6-0 | 2006-03-04 |
| Steven Asplund | 8-2-0 | 2026-08-08 |
| Steven Graham | 2-1-0 | 1997-05-30 |
| Steven Koslow | 6-1-0 | 2026-10-17 |
| Steven Nguyen | 10-2-0 | 2025-07-26 |
| Steven Peterson | 19-11-0 | 2023-03-25 |
| Steven Siler | 29-16-0 | 2014-07-26 |
| Stevie Lynch | 5-2-0 | 2007-06-16 |
| Stevie Ray | 23-9-0 | 2019-10-26 |
| Stewart Nicoll | 8-4-0 | 2026-07-18 |
| Stipe Miocic | 20-5-0 | 2024-11-16 |
| SuYoung You | 16-4-0 (2 NC) | 2026-03-14 |
| Sulangrangbo | 10-4-0 | 2026-01-31 |
| Sultan Aliev | 15-3-0 | 2019-04-20 |
| Suman Mokhtarian | 8-5-0 | 2019-12-21 |
| Sumudaerji | 20-7-0 (1 NC) | 2026-08-29 |
| Sung Bin Jo | 9-1-0 | 2019-06-01 |
| Syuri Kondo | 6-3-0 | 2019-06-22 |
| Taila Santos | 19-3-0 | 2023-08-26 |
| Takashi Sato | 16-7-0 | 2023-05-20 |
| Takenori Sato | 19-11-7 (1 NC) | 2014-09-20 |
| Tarec Saffiedine | 16-7-0 | 2017-06-17 |
| Tatiana Suarez | 13-1-0 | 2026-04-11 |
| Thiago Santos | 22-11-0 | 2022-08-06 |
| Thiago Silva | 19-6-0 (2 NC) | 2013-10-09 |
| Tiago dos Santos e Silva | 20-7-2 (1 NC) | 2016-12-09 |
| Tim Sylvia | 31-10-0 (1 NC) | 2008-02-02 |
| Tommy Speer | 21-7-0 | 2008-04-02 |
| Tony Sims | 12-4-0 | 2016-01-02 |
| Townsend Saunders | 0-2-0 | 1999-01-08 |
| Trevor Smith | 15-10-0 | 2019-12-07 |
| Uran Satybaldiev | 9-1-0 | 2025-08-23 |
| Valentina Shevchenko | 26-4-1 | 2025-11-15 |
| Vinicius Salvador | 14-7-0 | 2024-05-18 |
| Wade Shipp | 11-5-0 | 2004-04-02 |
| Wagner Silva | 6-3-0 | 2014-11-08 |
| Wanderlei Silva | 35-13-1 (1 NC) | 2013-03-02 |
| Wes Schultz | 9-4-0 | 2026-08-22 |
| Wes Sims | 24-14-1 (2 NC) | 2004-04-02 |
| Yana Santos | 17-8-0 (1 NC) | 2025-10-04 |
| Yuki Sasaki | 25-22-2 | 2006-08-17 |
| Yuta Sasaki | 21-6-2 | 2018-11-17 |
| Zachary Scroggin | 7-1-0 | 2024-11-09 |