| Fighter | Record | Last Bout |
|---|---|---|
| Jefferson Nascimento | 13-1-0 | 2026-06-27 |
| Jeisla Chaves | 8-1-0 | 2026-08-22 |
| Jeka Saragih | 14-5-0 | 2025-06-07 |
| JeongYeong Lee | 11-3-0 | 2025-05-10 |
| Jeremiah Wells | 14-4-1 | 2026-08-15 |
| Jeremy Stephens | 29-23-0 (1 NC) | 2026-05-09 |
| Jessica Andrade | 26-15-0 | 2025-08-16 |
| Jessica Penne | 14-9-0 | 2024-10-19 |
| Jessie Rosas | 8-1-0 | 2026-09-12 |
| Jesus Aguilar | 12-4-0 | 2026-03-07 |
| Jhonata Diniz | 9-2-0 | 2026-10-17 |
| Jim Miller | 39-19-0 (1 NC) | 2026-05-09 |
| Jimmy Crute | 14-4-2 | 2025-09-27 |
| Jimmy Flick | 17-9-0 | 2025-04-26 |
| Jiri Prochazka | 32-6-1 | 2026-04-11 |
| JJ Aldrich | 15-7-0 | 2026-09-12 |
| Joanderson Brito | 19-5-1 | 2026-09-19 |
| Joaquim Silva | 14-6-0 | 2025-09-13 |
| Joaquin Buckley | 21-8-0 | 2026-10-17 |
| Joe Kropschot | 9-3-0 | 2026-10-31 |
| Joe Pyfer | 16-3-0 | 2026-03-28 |
| Joe Solecki | 13-6-0 | 2025-01-11 |
| Joel Alvarez | 23-5-0 | 2026-08-15 |
| John Castaneda | 21-8-1 | 2026-09-26 |
| John Garza | 6-2-0 | 2026-07-11 |
| John Yannis | 10-5-0 | 2026-06-06 |
| Johnny Walker | 22-10-0 (1 NC) | 2026-10-03 |
| Jon Jones | 28-1-0 (1 NC) | 2024-11-16 |
| Jonathan Martinez | 19-6-0 | 2024-11-16 |
| Jonathan Micallef | 10-1-0 | 2026-05-02 |
| Jonathan Pearce | 14-7-0 | 2024-10-12 |
| JooSang Yoo | 9-1-0 | 2026-09-19 |
| Jordan Leavitt | 13-4-0 | 2026-06-06 |
| Jordan Vucenic | 13-4-0 | 2025-03-22 |
| Jose Aldo | 32-10-0 | 2025-05-10 |
| Jose Daniel Medina | 11-7-0 | 2026-02-28 |
| Jose Delano | 17-3-0 | 2026-04-04 |
| Jose Delgado | 12-2-0 | 2026-09-12 |
| Jose Johnson | 16-10-0 | 2025-01-11 |
| Jose Montanha | 7-1-0 | 2026-08-08 |
| Jose Ochoa | 9-2-0 (1 NC) | 2026-05-09 |
| Jose Souza | 9-1-0 | 2026-05-30 |
| Josefine Knutsson | 8-1-0 | 2024-12-14 |
| Joselyne Edwards | 18-6-0 | 2026-04-25 |
| Joseph Morales | 15-2-0 | 2026-09-12 |
| Josh Emmett | 19-7-0 | 2026-03-14 |
| Josh Hokit | 10-0-0 | 2026-06-14 |
| Joshua Van | 17-2-0 | 2026-09-19 |
| Josiah Harrell | 11-1-0 | 2026-09-26 |
| Josiane Nunes | 10-4-0 | 2025-03-15 |