| Fighter | Record | Last Bout |
|---|---|---|
| Mayra Bueno Silva | 10-7-1 (1 NC) | 2026-04-25 |
| Mehdi Baghdad | 11-5-0 | 2016-07-07 |
| Melsik Baghdasaryan | 8-4-0 | 2026-06-20 |
| Melton Bowen | 0-1-0 | 1994-12-16 |
| Michael Bisping | 30-9-0 | 2017-11-25 |
| Michel Batista | 4-1-0 (1 NC) | 2018-11-30 |
| Miguel Baeza | 10-4-0 | 2024-06-08 |
| Mike Breeden | 11-6-0 | 2023-10-21 |
| Mike Brown | 26-9-0 | 2013-08-17 |
| Mikey Burnett | 5-2-0 | 1999-01-08 |
| Mirsad Bektic | 13-4-0 | 2020-09-19 |
| Modestas Bukauskas | 21-7-0 | 2026-09-05 |
| Murilo Bustamante | 15-8-1 | 2002-05-10 |
| Nah-Shon Burrell | 15-7-0 (1 NC) | 2013-05-25 |
| Namsrai Batbayar | 10-2-0 | 2026-08-29 |
| Niklas Backstrom | 11-3-0 (1 NC) | 2015-06-20 |
| Oluwale Bamgbose | 6-4-0 | 2017-12-16 |
| Pat Barry | 8-7-0 | 2013-12-06 |
| Paul Bradley | 23-8-0 (2 NC) | 2011-11-12 |
| Paul Buentello | 35-17-0 | 2010-03-21 |
| Peter Barrett | 11-5-0 | 2020-12-12 |
| Phil Baroni | 15-18-0 | 2011-01-01 |
| Poliana Botelho | 8-5-0 | 2022-06-04 |
| Ramiz Brahimaj | 13-7-0 | 2026-08-15 |
| Randy Brown | 20-8-0 | 2026-04-11 |
| Raoni Barcelos | 22-5-0 | 2026-09-26 |
| Ray Borg | 13-5-0 | 2020-05-13 |
| Renan Barao | 34-9-0 (1 NC) | 2019-11-16 |
| Rob Broughton | 16-7-1 | 2011-11-05 |
| Robert Bryczek | 18-7-0 | 2026-09-26 |
| Rodolfo Bellato | 13-3-1 (1 NC) | 2026-09-26 |
| Roger Bowling | 12-6-0 (1 NC) | 2013-12-14 |
| Rogerio Bontorin | 16-4-0 (2 NC) | 2022-01-15 |
| Rolando Bedoya | 14-5-0 | 2025-09-27 |
| Roman Bogatov | 10-1-0 | 2020-07-11 |
| Ryan Bader | 23-5-0 | 2016-11-19 |
| Ryan Benoit | 10-8-0 | 2021-07-31 |
| Scott Baker | 1-1-0 | 1994-03-11 |
| Scott Bessac | 4-6-0 | 1995-12-16 |
| Sean Brady | 19-2-0 | 2026-11-07 |
| Seth Baczynski | 20-14-0 | 2015-04-11 |
| Shamar Bailey | 16-11-0 | 2011-11-19 |
| Shane Burgos | 15-3-0 | 2022-07-16 |
| Shauna Bannon | 7-3-0 | 2026-05-16 |
| Shayna Baszler | 15-11-0 | 2015-03-21 |
| Siyar Bahadurzada | 24-8-1 | 2019-09-28 |
| Stephan Bonnar | 15-9-0 | 2012-10-13 |
| Stephen Bass | 11-2-0 | 2011-12-03 |
| Steve Berger | 21-23-2 (1 NC) | 2002-06-22 |
| Steve Bosse | 12-2-0 | 2016-06-18 |