St. Mary's County, Maryland

St. Mary’s County, established in 1637, is a county located in the U.S. state of Maryland. As of the 2020 census, the population was 113,777. Its county seat is Leonardtown. The name is in honor of Mary, the mother of Jesus. St. Mary’s County is part of the Lexington Park, MD Metropolitan Statistical Area, which also is included in the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area. It is part of the Southern Maryland region.