The 23-year-old scored four goals and contributed one assist in four games played by the forward in the month under review.
The former Poitiers player beat off competitions from Sainte-Etienne Tunisia international Wahbi Khazri and Lyon's Tanguy Ndombele to succeed Paris Saint Germain attacker Kylian Mbappe who won the award in August.
Pepe becomes the first African player to collect the individual accolade after Morocco international Sofiane Boufal who scooped the prize in 2016 prior to switching to Premier League side Southampton.
The forward has been impressive since joining the Stade Pierre-Mauroy outfit in August 2017, scoring 20 goals in 47 appearances amid several other dazzling performances that have earned him comparison to PSG superstar Neymar.
He will be looking to continue the form after the international break when Lile take on Dijon in a league game on Saturday.