The Northern Ireland international, who has scored 21 goals for the Dons so far this season, made the shortlist for PFA Player of the Year and collected the AFC Player of the Year title.
McGinn told RedWeb: "It really was an easy decision for me to sign this extension.
"I'm enjoying my time at the club, the players, the management team and the staff throughout the club have made the last season a pleasure for me so I was more than happy to commit my future to the Dons.
"I would also like to thank the supporters who have welcomed me to the city and given not only me but the team fantastic backing this season.
"I didn't come here just to play out the time on my contract, I am here to help bring back some silverware to the club and I hope next season we can strive to deliver that for the supporters."
Read new Dons boss Derek McInnes's comments on RedWeb.