Stillwater is a city in Washington County, Minnesota, directly across the St. Croix River from the state of Wisconsin. It is the county seat of Washington County. Stillwater is part of the Twin Cities Metro Area. According to the United States Census Bureau, the city has a total area of 7.3 square miles (19 square kilometer), of which, 6.5 square miles (17 square kilometer) of it is land and 0.8 square miles (2.1 square kilometer) of it (11.37%) is water. State Highways 36, 95, and 96 are three of the main routes in the community.