Jay Dee "B.J." Penn III (born December 13, 1978) is an American former professional mixed martial artist and Brazilian Jiu-Jitsu practitioner. Penn competed in the Ultimate Fighting Championship (UFC) and in K-1. Penn was the first American Gold medalist of the World Jiu-Jitsu Championship. In mixed martial arts, Penn has competed in the Featherweight, Lightweight, Welterweight, Middleweight, and Heavyweight/Openweight divisions. A former UFC Lightweight Champion and UFC Welterweight Champion, he is the second of seven 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 "[through his] 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. During a meeting at the Hawaii State Department of Education building multiple board members and acting superintendent Keith Hayashi, were told by Penn, “You’re all gonna be gone when I’m governor!”
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.
His nickname "B.J." is a shortened version of another nickname "Baby Jay", which itself derives from the fact that Penn is the youngest of his brothers all named "Jay Dee Penn". B.J.'s father, who is Irish and English, named 3 of his 4 children "Jay Dee", while the fourth is Reagan. In order to avoid confusion each of the sons named "Jay Dee" goes by a nickname: "Jay" (Jay Dee Penn), "Jay Dee" (Jay Dee Penn II), and "Baby Jay" (Jay Dee Penn III). Penn's mother, Lorraine Shin, is of Hawaiian and Korean descent.
Being born in Hawaii, Penn takes much pride in his Hawaiian upbringing. Penn often plays Hawaiian music during his walk-out entrances, a combination of Hawaii ’78 into E Ala E, both performed by Hawaiian musician Israel Kamakawiwoʻole as a tribute to his Hawaiian heritage and respect for his opponents, fans and the fight game. Penn has also stated that he identifies strongly with his Korean roots and has traveled to South Korea to hold seminars. He also said that he gets his hot temper from his Korean side which helps him use this energy in his fights.
Penn has two daughters with the same mother. He says that they have never married and "it doesn't matter that much in Hawaii."
Penn is the co-author of Mixed Martial Arts: The Book of Knowledge, an instructional book on mixed martial arts fighting. Penn, along with Dave Weintraub, authored the autobiography Why I Fight: The Belt is Just an Accessory in 2010. The book debuted at #22 on the New York Times bestseller list. Penn also appeared in the film Never Surrender in 2009.Penn was also the subject of a Paternity Lawsuit in relation to his daughter, Mahina Amado, approximately a year after the girl's birth. On the 5th of October, 2021, Penn also announced his intention to run for governor in the 2022 Hawaii gubernatorial election.
Penn was born in Hawaii to Jay Dee Penn, who is of Irish American descent, and Lorraine Shin, who is of Korean and Hawaiian descent. At the age of 17, Penn began training in Brazilian Jiu-Jitsu after being introduced to it by his neighbor, Tom Callos. Callos had put up fliers in local gyms looking for people to train with, and B.J.'s father Jay Dee Penn had called Callos and said his boys were interested. Callos then taught B.J. and his brother what he knew. Shortly thereafter, B.J. moved to San Jose, California, to begin training at the Ralph Gracie BJJ academy with Dave Camarillo, with whom he lived and became close friends. It was here during his time in San Jose that he decided to pursue a martial arts career.