Marantao is a municipality in the province of Lanao del Sur.

According to the 2000 census, it has a population of 24,647 people in 3,598 households.

Marantao is politically subdivided into 34 barangays.

The climate is classified as Type IV which is characterized by more or less even distribution of rainfall throughout the year. Dry season is observed during the months from January to March and maximum rain period is from May to October.

Many are hopeful of finding oil and natural gas in Marantao. Drilling on Marantao is scheduled until 2008.