The 29-year-old claimed the honour after scoring a stunning 30-metre goal in the club’s 3-1 victory.
With the score level at 1-1 in the 59th minute, the African collected the ball outside the penalty area and fired a powerful right-footed shot into the top corner, leaving goalkeeper Nicola Leali helpless.
The goal was his first in four league appearances for the Yellow and Reds this season.
Okereke beat Modena striker Andrea Belotti and Cremonese youngster Adin Licina to the award.
The Nigerian forward joined Benevento on a free transfer in August after leaving fellow Serie B club Cremonese earlier this summer.
