| Fighter | Record | Last Bout |
|---|---|---|
| Al Iaquinta | 14-7-1 | 2021-11-06 |
| Alibi Idiris | 11-1-0 (1 NC) | 2026-02-21 |
| Anthony Ivy | 8-4-0 | 2020-09-12 |
| Blagoy Ivanov | 19-6-0 (1 NC) | 2023-07-01 |
| Brad Imes | 13-7-0 | 2007-04-07 |
| Chris Indich | 6-4-0 | 2014-06-28 |
| Damir Ismagulov | 24-3-0 | 2023-07-01 |
| Dan Ige | 19-11-0 | 2026-09-12 |
| Enson Inoue | 12-8-0 | 1997-05-30 |
| Fabiano Iha | 9-5-0 | 2001-09-28 |
| Guto Inocente | 7-4-0 | 2014-11-07 |
| Ian Entwistle | 9-3-0 | 2016-04-10 |
| Ian Freeman | 20-7-1 | 2003-06-06 |
| Ian Heinisch | 14-5-0 | 2021-07-24 |
| Ian Loveland | 18-10-0 | 2011-08-27 |
| Ian Machado Garry | 17-2-0 | 2026-08-15 |
| Ian McCall | 13-5-1 | 2015-01-31 |
| Iasmin Lucindo | 18-6-0 | 2025-08-09 |
| Ibo Aslan | 14-4-0 | 2025-12-06 |
| Icho Larenas | 6-5-0 | 2006-03-04 |
| Ignacio Bahamondes | 17-7-0 | 2026-09-12 |
| Igor Araujo | 25-9-0 (1 NC) | 2015-07-15 |
| Igor Pokrajac | 28-13-0 (1 NC) | 2016-04-10 |
| Igor Severino | 8-1-0 | 2024-03-23 |
| Igor Zinoviev | 4-1-2 | 1998-03-13 |
| Ihor Potieria | 20-8-0 | 2025-01-11 |
| Ike Villanueva | 18-14-0 | 2022-04-23 |
| Ikram Aliskerov | 18-2-0 | 2026-06-27 |
| Ikuhisa Minowa | 60-42-8 | 2000-04-14 |
| Ildemar Alcantara | 21-11-0 | 2015-07-15 |
| Ilia Topuria | 17-1-0 | 2026-06-14 |
| Iliarde Santos | 30-13-1 (1 NC) | 2013-10-09 |
| Ilimbek Akylbek Uulu | 10-3-0 | 2026-09-26 |
| Ilir Latifi | 17-9-0 (1 NC) | 2023-05-20 |
| Imanol Rodriguez | 7-0-0 | 2026-10-03 |
| Impa Kasanganay | 9-2-0 | 2021-09-18 |
| Ion Cutelaba | 20-12-1 (1 NC) | 2026-06-20 |
| Irene Aldana | 15-8-0 | 2024-09-14 |
| Irina Alekseeva | 5-4-0 | 2025-10-11 |
| Irwin Rivera | 10-6-0 | 2020-09-19 |
| Isaac Dulgarian | 7-2-0 | 2025-11-01 |
| Isaac Thomson | 9-3-0 | 2025-12-13 |
| Isaac Vallie-Flagg | 16-7-1 | 2014-11-22 |
| Isabela de Padua | 5-2-0 | 2019-11-16 |
| Islam Dulatov | 12-1-0 | 2025-07-19 |
| Islam Makhachev | 29-1-0 | 2026-08-15 |
| Ismael Bonfim | 20-7-0 | 2026-07-25 |
| Ismail Naurdiev | 25-8-0 | 2026-10-03 |
| Israel Adesanya | 24-6-0 | 2026-03-28 |
| Issei Tamura | 10-8-0 | 2013-03-16 |