The 155-pound bout will take place at UFC Fight Night, expected to take place in Las Vegas. The card is headlined by a bantamweight fight between T.J. Dillashaw and Cory Sandhagen.
Ferreira (17-3) is coming off a split decision loss to Beneil Dariush, who went on to book a high-profile fight against former interim champion Tony Ferguson on May 15. Prior to that loss, Ferreira, of Fortis MMA in Dallas, had won six in a row.
Gillespie (13-1) was supposed to face New Zealand's Brad Riddell on March 20, but the bout was pulled on the day of the fight due to Covid-19 protocols. Fighting out of Long Island, New York, Gillespie is 6-1 in the UFC, but is coming off a knockout loss to Kevin Lee in late 2019.
Ferreira and Gillespie are the UFC's Nos. 12 and 15-ranked lightweights, respectively.