Deer Lake is an unorganized territory in Itasca County, Minnesota, United States.

The unincorporated community of Suomi is located within Deer Lake Unorganized Territory.

Nearby towns include Deer River, Cohasset, and Grand Rapids.

At the 2000 census there were 3,286 people, 1,304 households, and 993 families living in the unorganized territory.

There were 2,154 housing units at an average density of 11.8 per square mile (4.6/km2).