UFC 331

The event will mark the promotion's sixth visit to Los Angeles and first since UFC 227 in August 2018. Initial reports had speculated that the event may have been held at the Intuit Dome in Inglewood, California or be part of the promotion's Noche UFC 4 celebration of Mexican Independence Day in Glendale, Arizona.

A UFC Flyweight Championship rematch between current champion Joshua Van and former champion Alexandre Pantoja is scheduled to headline the event. They previously competed in December 2025 at UFC 323, where Van won the belt via technical knockout 26 seconds into the first round as a result of an arm injury sustained by Pantoja.

A five-round lightweight bout between Arman Tsarukyan and Maurício Ruffy is scheduled to serve as the co-main event. Tsarukyan was initially expected to face former UFC Lightweight Champion Charles Oliveira also in a five-round lightweight bout, with early reports indicating that Oliveira would defend his symbolic "BMF" (baddest motherfucker) title, but the bout was later changed to a non-title contest. Oliveira and Tsarukyan previously met in April 2024 at UFC 300, where Tsarukyan won via split decision. On August 5, the promotion announced that Tsarukyan would instead face Ruffy. The withdrawal came just days after the death of Oliveira's longtime teammate, UFC flyweight Allan Nascimento, although no official reason for Oliveira's withdrawal was given.

A UFC Women's Bantamweight Championship bout between the reigning champion Kayla Harrison (who is also a 2012 and 2016 Olympic gold medalist in judo; and a two-time PFL women's lightweight tournament champion) and former two-time champion Amanda Nunes, who also held the UFC Women's Featherweight Championship, was reportedly planned for the event. However, the bout is postponed for undisclosed reasons. The bout was originally scheduled for UFC 324 in January 2026. However, Harrison withdrew from the bout after being diagnosed with herniated discs in her neck, which required surgery.

A bantamweight bout between former UFC Bantamweight Championship challenger Marlon Vera and Charles Jourdain is scheduled to take place at the event. The bout was originally scheduled to take place at UFC Fight Night: du Plessis vs. Usman in July, but was moved to this event for undisclosed reasons.

A heavyweight bout between former interim UFC Heavyweight Championship challenger Curtis Blaydes and former LFA Heavyweight Champion Waldo Cortes-Acosta was scheduled for the event. However, the bout was actually scheduled to take place one week prior at UFC Fight Night: Silva vs. Delgado.

A lightweight rematch between former lightweight title challenger Renato Moicano and former UFC Featherweight Championship challenger Brian Ortega was scheduled for the main card. However, days before the event, Ortega had to withdraw due to a suspected eye injury, so Moicano was re-scheduled to headline UFC Fight Night: Moicano vs. Nolan against Tom Nolan. The pair previously met in a featherweight bout at UFC 214 in July 2017, where Ortega won via third‑round guillotine choke. They were previously expected to rematch at UFC 326 in March, but Ortega withdrew due to injury and Moicano was later moved to headline UFC Fight Night: Moicano vs. Duncan one month afterward.