Dahlgren is a small city located in King George County, Virginia, United States. It is situated on the Northern Neck Peninsula, just east of the Potomac River. Dahlgren is primarily known for the Dahlgren Naval Surface Warfare Center, a US Navy installation that conducts research and development in various fields including naval warfare and weapons systems. The city has a population of around 2,655 residents according to the 2010 census. In addition to its military presence, Dahlgren offers a small-town atmosphere with a few local businesses and parks for residents to enjoy.