Youngest champions: since 2001
Youngest fighters to win an undisputed UFC title, by age on the day.
Reigns are derived from championship bouts. When a belt was vacated or stripped outside a title fight, the reign is shown ending at the next title fight in that division, so a few run long; a title awarded without a fight (José Aldo's in 2010, for one) starts at the champion's first UFC title fight.
102 fighters.
| # | Fighter | Age | Division | Won | Ended |
|---|---|---|---|---|---|
| 101 | Randy Couture | 40 years, 96 days | Light Heavyweight | Sep 26, 2003 | Jan 31, 2004 |
| 102 | Glover Teixeira | 42 years, 2 days | Light Heavyweight | Oct 30, 2021 | Jun 11, 2022 |