St. Agatha (French: Sainte-Agathe) is a town in Aroostook County, Maine, United States.

There were 497 housing units at an average density of 16.8 per square mile (6.5/km2).

35.3% of all households were made up of individuals, and 16.2% had someone living alone who was 65 years of age or older.

There were 460 housing units at an average density of 15.6 per square mile (6.0/km2).

The racial makeup of the town was 99.63% White, 0.12% Native American, 0.12% Pacific Islander, and 0.12% from two or more races.

28.3% of all households were made up of individuals, and 14.6% had someone living alone who was 65 years of age or older.