Mahtomedi is a city located in Washington County, Minnesota. As of the 2000 census, the city had a total population of 7,563. Mahtomedi is considered to be a suburb of St. Paul, the State Capital, and is located between St. Paul and Stillwater, the birthplace of Minnesota.
According to the United States Census Bureau, the city has a total area of 13.0 km2 (5.0 mi2). 9.3 km2 (3.6 mi2) of it is land and 3.7 km2 (1.4 mi2) of it is water. The total area is 28.23% water.