The bout between the top middleweights was officially announced by representatives of the organization.
Marvin Vettori, 30, has been on a steady win-loss streak for the past three years, and this time he returns to the octagon after a disappointing performance last June, losing a unanimous decision to Jared Cannonier.
Brendan Allen, 28, picked up his sixth straight win in the UFC in November, finishing Scotsman Paul Craig with a third-round rear-naked choke.
The Italian and American are currently ranked fifth and eighth in the UFC’s middleweight rankings, respectively.