The fighters were originally supposed to meet on May 6 at UFC 288, but a minor shoulder injury forced the Brazilian to pull out of the fight.
Oliveira (33-9) will look to get back on track after an early loss to Islam Makhachev last October that ended his 11-game win streak.
Dariush (33-9) hasn't lost since 2018. The American has eight victories in a row, including the finishes of Drew Dober, Frank Camacho, Drakkar Klose and Scott Holtzman. Beneil previously stated that the promotion had promised him a title shot if he won the upcoming fight.
Recall that UFC 289 will headline the third fight between women's bantamweight champion Amanda Nunes and Julianne Peña.