UFC on ESPN 55: Nicolau vs. Perez was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on April 27, 2024, at the UFC Apex facility, in Enterprise, Nevada, United States. A flyweight match between Matheus Nicolau and UFC Flyweight Championship challenger Alex Perez served as the headliner.
| Actor | Role |
|---|---|
 Alex PerezSelf | Self |
 Matheus NicolauSelf | Self |
| BBogdan GuskovSelf | Self |
| RRyan SpannSelf | Self |
 Karine SilvaSelf | Self |
 Ariane Lipski da SilvaSelf | Self |
| JJhonata DinizSelf | Self |
 Austen LaneSelf | Self |
 David OnamaSelf | Self |
 Jonathan PearceSelf | Self |
 Uroš MedićSelf | Self |
 Tim MeansSelf | Self |
 Victor HenrySelf | Self |
 Rani YahyaSelf | Self |
 Austin HubbardSelf | Self |
| MMichal FiglakSelf | Self |
 Don'Tale MayesSelf | Self |
 Caio MachadoSelf | Self |
 Ketlen SouzaSelf | Self |
| MMarnic MannSelf | Self |
| CChris PadillaSelf | Self |
| JJames LlontopSelf | Self |
| IIvana PetrovićSelf | Self |
 Na LiangSelf | Self |
 Hayisaer MaheshateSelf | Self |
 Gabriel BenítezSelf | Self |