Edgemoor is a census-designated place in New Castle County, Delaware, United States. The population was 5,677 at the 2010 census. Edgemoor is located at 39°45′00″N 75°29′59″W / 39.75000°N 75.49972°W. According to the United States Census Bureau, the CDP has a total area of 1.8 square miles, of which 1.8 square miles is land and 0.55% is water.