UFC 291: Poirier vs. Gaethje 2 was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on July 29, 2023, at the Delta Center in Salt Lake City, Utah, United States. A lightweight rematch between former interim UFC Lightweight Champions Dustin Poirier and Justin Gaethje (also former WSOF Lightweight Champion) headlined the event. They also competed for the symbolic "BMF" (baddest motherfucker) title, which was vacated after the original holder Jorge Masvidal retired in April. The pairing first met at UFC on Fox: Poirier vs. Gaethje in April 2018 which Poirier won by fourth-round TKO.