Jay Dee "B.J." Penn III is an American former professional mixed martial art fighter and 5th degree black belt Brazilian jiu-jitsu (BJJ) practitioner.
Prior to his MMA career, Penn was known as the first non-Brazilian to win the World Jiu-Jitsu Championship at black belt level. In mixed martial arts, Penn has competed in the Ultimate Fighting Championship (UFC) and in K-1 in the Featherweight, Lightweight, Welterweight, Middleweight, and Heavyweight/Openweight divisions. A former UFC Lightweight Champion and UFC Welterweight Champion, he is the second of nine fighters in UFC history to win titles in multiple weight classes. Penn fought to a draw against Caol Uno in the UFC 41 Lightweight Tournament. Through his tenures as champion, Penn unofficially unified the UFC Lightweight Championship (against Sean Sherk) and broke the all-time lightweight title defense record. In 2015, Penn was made the inaugural inductee into the Modern-era wing of the UFC Hall of Fame.
Penn was considered one of the top pound-for-pound mixed martial artists in the world early in his career and holds victories over opponents such as Din Thomas, Caol Uno, Paul Creighton, and Matt Serra. Penn won the Rumble on the Rock Lightweight Championship in K-1. He submitted long-reigning then-champion Matt Hughes to capture the UFC Welterweight Championship.
Following a period in which Penn competed exclusively for K-1, he returned to the UFC and won the UFC Lightweight Championship. He made a record three subsequent title defenses before losing his title to Frankie Edgar.
UFC President, Dana White, credits Penn with bringing the lower weight divisions into the mainstream of mixed martial arts; he describes Penn as "the first crossover pay-per-view star for the Ultimate Fighting Championship's lighter weight divisions", as well as saying that " accomplishments, B.J. Penn built the 155-pound division".
Penn announced his candidacy for governor of Hawaii in the 2022 Hawaii gubernatorial election in 2021.
Penn is regarded as one of the best competitors in the UFC's history. However, he has been criticized for continuing to fight past his prime, including an eight fight winless streak from 2011 to 2019.
