Square Lake is an unorganized territory in Aroostook County, Maine, United States.

There are 10 townships within the unorganized territory, plus one (T14R6 WELS) that is shared with Northwest Aroostook.

As of the 2000 census,[4] there were 615 people, 277 households, and 193 families living in the unorganized territory.

There were 1,086 housing units, at an average density of 2.8 per square mile (1.1/km2).

In the unorganized territory, 24.5% of all households were made up of individuals, and 10.1% had someone living alone who was 65 years of age or older.