Ayew picked up two yellow cards in the space of two minutes soon after coming on as a substitute in his team's 1-1 draw at Evian Thonon Gaillard.
Team-mate Kassim Abdallah, who was also sent off against Evian, was handed a two-match ban but with one game suspended.
OM, who are third in Ligue 1 - eight points behind leaders PSG - host Valenciennes on Saturday and travel to the Parc des Princes next weekend.