Platt has scored 18 goals this season and beat strike-partner Izale McLeod and captain Keith Andrews (also ex-Walsall) to the players' award.
The night caps a fantastic season for Platt, who had never reached double figures in the goal-scoring charts before this term. He became the first MK Dons player to score a hat-trick when he bagged a treble against Barnet in January.