Bethesda () is an unincorporated, census-designated place in southern Montgomery County, Maryland, United States. It is located just northwest of Washington, D.C. According to the 2020 census, the community had a total population of 68,056. It takes its name from a local church, the Bethesda Meeting House (1820, rebuilt 1849), which in turn took its name from Jerusalem's Pool of Bethesda. The National Institutes of Health's main campus and the Walter Reed National Military Medical Center are in Bethesda, in addition to several corporate and government headquarters.