The 125-pound contest will take place at UFC 276, which is expected to be held at T-Mobile Arena in Las Vegas. The UFC has not announced a main event for the card.
Eye (15-10) is a former title challenger who is looking to snap a three-fight skid. The 35-year-old was scheduled to face Manon Fiorot earlier this month but was forced to withdraw because of injury. She has not fought since losing by unanimous decision to Jennifer Maia in July.
It's a major opportunity for O'Neill (9-0), who improved to 4-0 in UFC with a split-decision win over Roxanne Modafferi in February. Originally from Australia, by way of Scotland, O'Neill now trains out of Las Vegas and is considered one of the top prospects in the division. She made her UFC debut in 2021 and finished three consecutive opponents that year.
Eye and O'Neill are UFC's No. 10- and No. 12-ranked flyweights, respectively.