Dustin Glenn Poirier (born January 19, 1989) is a retired American professional mixed martial artist renowned for competing in the Lightweight division of the Ultimate Fighting Championship (UFC). He is widely regarded as one of the greatest lightweights in MMA history. Over his career, Poirier held the Interim UFC Lightweight Championship and challenged three times for the undisputed UFC Lightweight title. He also vied twice for the UFC’s BMF (Baddest Motherf***er) title. Poirier shares the record for the most knockout or technical knockout wins in the UFC lightweight division, tied with Drew Dober. Born and raised in Lafayette, Louisiana, Poirier is of Cajun descent. He began his professional MMA career in 2009, rapidly accumulating an undefeated 7–0 record in regional promotions primarily located in Louisiana and the southern United States. His early career is featured in the documentary *Fightville*. Poirier debuted in World Extreme Cagefighting (WEC) in 2010 before transitioning to the UFC following the WEC-UFC merger. Throughout his UFC tenure, Poirier compiled a professional record of 30 wins and 10 losses, achieving 15 wins by knockout and 8 by submission. Known by the nickname "The Diamond," he fought with a southpaw stance and trained with American Top Team. Poirier’s technical skill, resilience, and exciting fighting style earned him immense popularity and respect within the MMA community. Poirier officially retired after UFC 318 in 2023, concluding a distinguished career marked by high-profile bouts against top contenders such as Conor McGregor and Islam Makhachev. His legacy includes not only his in-cage achievements but also philanthropic efforts outside the octagon. As of 2025, Poirier remains a celebrated figure in mixed martial arts, with a strong likelihood of future UFC Hall of Fame induction[1][5][6].