| Fighter | Record | Last Bout |
|---|---|---|
| Jeremy Horn | 91-22-5 (1 NC) | 2009-01-17 |
| Jeremy Jackson | 9-5-0 | 2006-11-11 |
| Jeremy Kennedy | 11-1-0 | 2018-02-10 |
| Jeremy Kimball | 15-8-0 | 2018-07-22 |
| Jeremy Larsen | 8-5-0 | 2013-10-19 |
| Jermaine Andre | 14-4-0 | 2000-03-10 |
| Jerome Rivera | 10-6-0 | 2021-07-10 |
| Jerrod Sanders | 16-3-0 (1 NC) | 2016-07-07 |
| Jerry Bohlander | 11-4-0 | 1999-01-08 |
| Jess Liaudin | 20-11-0 | 2008-10-18 |
| Jessamyn Duke | 3-5-0 (1 NC) | 2015-07-25 |
| Jesse Bongfeldt | 16-5-1 | 2011-06-11 |
| Jesse Butler | 12-6-0 | 2024-06-08 |
| Jesse Forbes | 15-5-0 | 2010-05-29 |
| Jesse Lennox | 14-4-0 | 2010-06-12 |
| Jesse Ronson | 21-12-0 (1 NC) | 2022-10-01 |
| Jesse Sanders | 23-7-0 | 2009-04-01 |
| Jesse Strader | 5-3-0 | 2022-02-19 |
| Jesse Taylor | 31-15-0 | 2017-07-07 |
| Jessica Aguilar | 20-8-0 | 2019-03-30 |
| Jessica Eye | 15-11-0 (1 NC) | 2022-07-02 |
| Jessica Rakoczy | 1-5-0 (1 NC) | 2015-04-25 |
| Jessica-Rose Clark | 11-9-0 (1 NC) | 2023-05-13 |
| Jessin Ayari | 16-6-0 | 2020-10-03 |
| Jesus Pinedo | 16-5-1 | 2019-03-23 |
| Ji Yeon Kim | 9-7-2 | 2023-05-13 |
| Jianping Yang | 11-4-1 | 2014-08-23 |
| Jim Alers | 13-3-0 (1 NC) | 2016-07-23 |
| Jim Mullen | 0-2-0 | 1997-02-07 |
| Jim Wallhead | 29-11-0 | 2017-06-03 |
| Jimi Manuwa | 17-6-0 | 2019-06-01 |
| Jimmie Rivera | 23-5-0 | 2021-02-27 |
| Jimmy Quinlan | 3-1-1 | 2013-04-13 |
| Jimy Hettes | 11-3-0 | 2015-04-18 |
| Jin Soo Son | 9-4-0 | 2019-07-20 |
| Jinh Yu Frey | 11-10-0 | 2023-10-21 |
| Joachim Christensen | 14-6-0 | 2017-06-25 |
| Joanna Jedrzejczyk | 16-5-0 | 2022-06-11 |
| Joanne Wood | 17-8-0 | 2024-03-09 |
| Joao Pierini | 4-1-0 | 2002-06-22 |
| Joao Roque | 7-2-4 | 2000-06-09 |
| Joao Zeferino | 21-9-0 | 2013-09-04 |
| Joby Sanchez | 11-4-0 | 2018-11-10 |
| Jocelyn Jones-Lybarger | 6-4-0 | 2017-01-15 |
| Jodie Esquibel | 6-6-0 | 2019-08-17 |
| Joe Brammer | 7-3-1 | 2010-05-29 |
| Joe Charles | 6-13-0 | 1997-12-21 |
| Joe Doerksen | 51-16-0 | 2010-12-11 |
| Joe Duffy | 16-5-0 | 2020-07-18 |
| Joe Ellenberger | 15-2-0 | 2014-12-13 |