Sonsón is a municipality in the Colombian department of Antioquia. Sonsón is located in Eastern Antioquia. It is one of the seats of the R…Sonsón is a municipality in the Colombian department of Antioquia. Sonsón is located in Eastern Antioquia. It is one of the seats of the Roman Catholic Diocese of Sonsón–Rionegro. Sonsón celebrates "Las Fiestas Del Maíz"- during the month of August, being the most traditional, historical and representative festival in western Colombia. The population was estimated to be 33,598 in 2020.