Prince Frederick is an unincorporated community and census-designated place (CDP) in Calvert County,Maryland, United States. As of the 2010 census, the population of Prince Frederick was 2,538, up from 1,432 at the 2000 census.
Prince Frederick has served as the county seat of Calvert County since 1722, when officials chose a plot of land known as "Williams' Old Field" as the spot for the new county courthouse. (Contemporary references to the piece of land include an upscale dining restaurant named Old Field Inn, and a street in Prince Frederick named "Old Field Lane.") The original courthouse was finally completed in 1732. The town was most likely named for George II's son Frederick, who was Prince of Wales during the time of the town's original conception. In the War of 1812, Commodore Joshua Barney's Chesapeake Bay Flotilla found refuge from the advancing British in St. Leonard's Creek, several miles south of Prince Frederick, in June 1814. While laying siege to Barney's force, the British under the command of Admiral Sir Alexander Cochrane plundered and destroyed the area nearby, including burning the town of Prince Frederick. In 1882, Prince Frederick burned a second time, when a massive fire destroyed virtually the entire town and its courthouse. A new courthouse was erected on the same spot, and remains the center of Calvert County's government to this day.