Ampatuan is a 4th class municipality in the province of Maguindanao with a land area of 447,228.94 hectares. . It was created by virtue of Executive Order No. 82. It is under the supervision of the Autonomous Region in Muslim Mindanao (ARMM) since November 19, 1989 pursuant to Republic act No. 6734 dated June 8, 1989.

According to the 2000 census, it has a population of 32,907 people in 6,453 households.

Ampatuan is politically subdivided into 11 barangays.

Characterized by a more or less even distribution of rainfall throughout the year, the coldest months in the province are December and January. The warm season is from March to June.