Who was the youngest fighter to win a UFC championship?

Jon Jones was the youngest fighter to win a UFC championship, capturing the light heavyweight title at age 23 years and 242 days.

Jones won the vacant championship by defeating Mauricio Rua at UFC 128 on March 19, 2011. He stopped Rua by technical knockout in the third round after dominating the contest with wrestling, striking, and ground attacks.

The victory made Jones the youngest UFC champion in history. The record is based on the fighter’s age on the date the title was won, rather than on the age when a title fight was announced or scheduled.

Jones became one of the defining champions of the light heavyweight division. His career also included interim-title periods and a later move to heavyweight, so individual records should be distinguished from his overall championship history.