Leonardtown is a town in and the county seat of St. Mary's County, Maryland, United States. The population was 2,930 at the 2010 census. Leonardtown is perhaps most famous for the national oyster-shucking championship that is held annually at the St. Mary's County fairgrounds.
Historic Leonardtown includes both a large public high school and a public middle school Leonardtown Middle School as well as a Catholic high school and an elementary school Leonardtown Elementary School, offices of the county government, and St. Mary's Hospital which serves the healthcare needs of the county. The College of Southern Maryland maintains a growing satellite campus within city limits, including an aquatic center. An upscale home development located in the Breton Bay area is just outside town, notable for both its country club golf course and swimming pool.
Leonardtown's population has grown significantly since 1990 as a result of the town's proximity to Patuxent River Naval Air Station and the Washington metro area.