Ampatuan, officially the Municipality of Ampatuan, is a 4th class municipality in the province of Maguindanao del Sur, Philippines. According to the 2020 census, it has a population of 28,941 people.

Maguindanao del Sur, officially the Province of Maguindanao del Sur, is a landlocked province in the Philippines located in the Bangsamoro Autonomous Region in Muslim Mindanao in Mindanao. Its capital is the municipality of Buluan near the city of Tacurong in the neighboring province of Sultan Kudarat. It borders Cotabato province to the east, Maguindanao del Norte to the west, and Sultan Kudarat to the south.