Mamasapano, officially the Municipality of Mamasapano, is a municipality in the province of Maguindanao del Sur, Philippines. According to th…Mamasapano, officially the Municipality of Mamasapano, is a municipality in the province of Maguindanao del Sur, Philippines. According to the 2020 census, it had a population of 27,807. This municipality was formerly a barangay of the town of Shariff Aguak. However, by virtue of Republic Acts No. 6646/7160 and Muslim Mindanao Autonomy Act No. 54 dated April 27, 1997, issued on December 2, 1998, COMELEC Resolution No. 3051/3052 and Plebiscite conducted on October 31, 1998, the Municipality of Mamasapano then became the 11th municipality in the 2nd District of Maguindanao. The newly created municipality has eighteen barangays taken from its mother municipality of Shariff Aguak.