The fights for UFC Las Vegas or UFC Fight Night 221 event were made official at the weigh-in event on March 10, 2023.
A big bantamweight fight was the headliner with #2 Petr Yan and #3 ranked Merab Dvalishvili clashing in a high-stakes bout. Yan came in net at 136 lbs while Dvalishvili came in at 134.5 lbs. For the co-main event, Alexander Volkov came in at 258 lbs while Alexander Romanov weighed at 264.5 lbs, 20 lbs heavier than his last bout.
Nikita Krylov and Ryan Spann came in at 213 lbs in their rescheduled bout. For their UFC debut, Vitor Petrino weighed at 204 lbs, Karl Williams came in at 240 lbs while Sedriques Dumas weighed at 184.5 lbs. Check complete weigh-in results from UFC Fight Night 221 or UFC Las Vegas: Yan vs Dvalishvili event below.
- Petr Yan (136 lbs) vs Merab Dvalishvili (134.5 lbs)
- Alexander Romanov (264.5 lbs) vs Alexander Volkov (258 lbs)
- Nikita Krylov (213 lbs) vs Ryan Spann (213 lbs)
- Austin Lingo (145.5 lbs) vs Ricardo Ramos (154 lbs)**
- Jonathan Martinez (135.5 lbs) vs Said Nurmagomedov (136 lbs)
- Vitor Petrino (204 lbs) vs Anton Turkalj (205 lbs)
- Lukasz Brzeski (245 lbs) vs Karl Williams (240 lbs)
- Raphael Assuncao (136 lbs) vs Davey Grant (136 lbs)
- Sedriques Dumas (184.5 lbs) vs Josh Fremd (186 lbs)
- Mario Bautista (136 lbs) vs Guido Cannetti (136 lbs)
- Tony Gravely (136 lbs) vs Victor Henry (136 lbs)
- JJ Aldrich (125.5 lbs) vs Ariane Lipski (125.5 lbs)
- Tyson Nam (125.5 lbs) vs Bruno Silva (125.5 lbs)
- Jared Gooden (177 lbs)** vs Carlston Harris (169.5 lbs)
Jared Gooden missed weight for welterweight bout by 6 lbs. The fight will continue as a catchweight bout at 177 lbs and Gooden will pay fine at 30% of his purse to Harris.
Ricardo Ramos missed weight for featherweight bout by 8 lbs. The bout was cancelled after this.