UFC Fight Night: Dern vs. Hill

UFC Fight Night: Dern vs. Hill (also known as UFC Fight Night 223, UFC Vegas 73, and UFC on ESPN+ 81) was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on May 20, 2023, at the UFC Apex facility in Enterprise, Nevada, part of the Las Vegas Metropolitan Area, United States.

Background
A women's bantamweight rematch between former UFC Women's Bantamweight Championship challenger Raquel Pennington and Irene Aldana was expected to headline the event. The pair previously met at UFC on ESPN: dos Anjos vs. Edwards in 2019 which Pennington won by split decision. They were also briefly expected to headline UFC on ESPN: Vera vs. Sandhagen, but the bout never materialized. In turn, Aldana was pulled from the contest in early May in order to serve as a replacement in a UFC Women's Bantamweight Championship bout against current champion Amanda Nunes at UFC 289. Pennington will serve as a backup for that event.

As a result, a women's strawweight bout between Mackenzie Dern and former Invicta FC Strawweight Champion Angela Hill was moved from UFC on ABC: Rozenstruik vs. Almeida one week prior to instead headline this event.

A women's strawweight bout between former Invicta FC Strawweight Champion Emily Ducote and Polyana Viana was originally scheduled for UFC Fight Night: Song vs. Simón. The pairing was eventually rescheduled for this event for undisclosed reasons. In turn, Viana withdrew from the bout and was replaced by former LFA Women's Strawweight Champion Lupita Godinez at a catchweight of 120 pounds.

A middleweight bout between Abdul Razak Alhassan and Brunno Ferreira was expected to take place at this event. However, the bout was moved to UFC on ESPN: Strickland vs. Magomedov for unknown reasons.

A flyweight bout between Clayton Carpenter and Stephen Erceg was expected to take place at this event, but it was postponed due Erceg having visa issues.

At the weigh-ins, Vanessa Demopoulos and Orion Cosce missed weight. Demopoulos weighed in at 117.5 pounds and Cosce weighed in at 172.5 pounds, both one and half pounds over the women's strawweight and welterweight non-title fights limit respectively. Both bouts proceeded at catchweight with both being fined 20 percent of their purses, which went to their opponents: former UFC Women's Strawweight Championship challenger (also former KSW Women's Flyweight Champion) Karolina Kowalkiewicz and Gilbert Urbina respectively.

Bonus awards
The following fighters received $50,000 bonuses.
 * Fight of the Night: Mackenzie Dern vs. Angela Hill
 * Performance of the Night: Carlos Diego Ferreira and Viacheslav Borschev