The UFC 257 pay-per-view event is the first on the company’s 2021 schedule. The promotion has not announced a location for the event or a main event, although UFC president Dana White has said the event is earmarked for Conor McGregor‘s return to the Octagon against Dustin Poirier.
Waterson (18-8) is one of the most established names of the strawweight division, with a 6-4 record in the UFC dating back to 2015. The former Invicta FC champion was knocking on the door of title contention in 2019 before she suffered back-to-back decision losses to former champions Joanna Jedrzejczyk and Carla Esparza.
Fighting out of Jackson Wink MMA in Albuquerque, New Mexico, Waterson has since rebounded from the two-fight skid with a win over Angela Hill.
Ribas (10-1) is one of the most promising prospects in the division. The 27-year-old Brazilian is undefeated since signing with the UFC last year, and has taken out the likes of Emily Whitmire, Mackenzie Dern, Randa Markos and Paige VanZant. She finished VanZant with a first-round armbar at UFC 251 in July.