Waldorf is an unincorporated community and census-designated place in Charles County, Maryland, United States. It is 23 miles (37 km) south-southeast of Washington, D.C. The population of the census-designated area (now including the large planned community of St. Charles) was 67,752 at the 2010 census.
Waldorf's original name was Beantown. During his post assassination flight, John Wilkes Booth told a road sentry he was headed to his home in Charles County near Beantown and was allowed to proceed. In 1880, the General Assembly of Maryland by an act changed the name to "Waldorf" in honor of William Waldorf Astor (1848–1919), the great-grandson of John Jacob Astor (1763–1848), who was born in Walldorf,Palatinate, Germany. On July 29, 1908, the city of Plumb Valley inWaseca County, Minnesota, changed its name to Waldorf after Waldorf, Maryland. Once a tobacco market village, Waldorf came to prominence in the 1950s as a gambling destination after slot machines were legalized in Charles County in 1949. The boom lasted until 1968 when gambling was once again outlawed. Its subsequent substantial growth as a residential community began with a 1970 loan package from the Department of Housing and Urban Development which fueled the giant planned community of St. Charles, south of Waldorf. St. Catharine, or the Dr. Samuel A. Mudd House, was listed on the National Register of Historic Places in 1974.