| Fighter | Record | Last Bout |
|---|---|---|
| Jason Brilz | 22-6-1 | 2011-11-19 |
| Javid Basharat | 15-2-0 (1 NC) | 2026-02-07 |
| Jerry Bohlander | 11-4-0 | 1999-01-08 |
| Jesse Bongfeldt | 16-5-1 | 2011-06-11 |
| Jesse Butler | 12-6-0 | 2024-06-08 |
| Joanderson Brito | 19-5-1 | 2026-09-19 |
| Joaquin Buckley | 21-8-0 | 2026-10-17 |
| Joe Brammer | 7-3-1 | 2010-05-29 |
| Joey Beltran | 17-14-0 (1 NC) | 2013-10-09 |
| Johnny Bedford | 21-13-1 (1 NC) | 2014-09-13 |
| Jonathan Brookins | 16-10-0 | 2012-12-15 |
| Joseph Benavidez | 28-8-0 | 2021-03-06 |
| Josh Barnett | 35-8-0 | 2016-09-03 |
| Josh Bryant | 15-4-0 | 2010-06-19 |
| Joshua Burkman | 28-16-0 (1 NC) | 2018-02-18 |
| Jules Bruchez | 1-2-0 | 2008-12-13 |
| Junie Browning | 5-6-0 | 2009-04-01 |
| Justin Buchholz | 15-10-0 | 2010-02-06 |
| KB Bhullar | 8-2-0 | 2021-05-01 |
| Keith Berish | 5-1-0 (1 NC) | 2016-12-09 |
| Kevin Borjas | 11-6-0 | 2026-08-29 |
| Kevin Burns | 12-7-0 | 2009-12-12 |
| Kyle Bochniak | 8-5-0 | 2019-10-18 |
| Kyle Bradley | 19-12-0 (1 NC) | 2010-01-11 |
| Lance Benoist | 7-2-0 | 2014-06-07 |
| Lucas Brennan | 11-3-0 | 2026-04-25 |
| Lukasz Brzeski | 9-7-1 (1 NC) | 2025-07-19 |
| Luke Barnatt | 13-4-0 | 2015-05-16 |
| Mads Burnell | 9-3-0 | 2018-05-27 |
| Magomed Bibulatov | 14-2-0 | 2019-02-02 |
| Mandy Bohm | 8-2-0 (1 NC) | 2023-05-13 |
| Manny Bermudez | 14-2-0 | 2019-10-18 |
| Mara Romero Borella | 12-9-0 (2 NC) | 2020-09-19 |
| Marc-Andre Barriault | 17-11-0 (1 NC) | 2026-10-17 |
| Marcin Bandel | 15-7-0 | 2015-04-11 |
| Marcio Barbosa | 19-2-0 | 2026-08-22 |
| Marco Beltran | 8-6-0 | 2017-10-07 |
| Marcus Bossett | 1-3-0 | 1996-12-07 |
| Marcus Brimage | 7-7-0 | 2015-07-18 |
| Marcus Buchecha | 5-3-1 | 2026-04-25 |
| Marek Bujlo | 6-1-0 | 2025-11-22 |
| Mario Bautista | 18-3-0 | 2026-07-11 |
| Mark Bocek | 12-5-0 | 2014-04-16 |
| Martin Bravo | 11-3-0 | 2019-09-21 |
| Martin Buday | 16-2-0 | 2025-07-26 |
| Matt Bessette | 22-9-0 (1 NC) | 2018-07-06 |
| Matt Brown | 26-19-0 | 2023-05-13 |
| Matt Van Buren | 7-6-0 | 2015-01-18 |
| Maximo Blanco | 12-8-1 (1 NC) | 2016-09-17 |
| Maycee Barber | 15-3-0 | 2026-03-28 |