The United States Naval Surface Warfare Center Dahlgren Division (NSWCDD), named for Rear Admiral John A. Dahlgren, is located in King George County, Virginia, in close proximity to the largest fleet concentration area in the Navy. NSWCDD is part of the Naval Surface Warfare Centers under the Naval Sea Systems Command (NAVSEA). NSWCDD was initially established 16 October 1918 as a remote extension of Maryland's Indian Head Proving Ground used for testing naval guns. The Dahlgren site was named the Lower Station, Dahlgren Naval Proving Ground when it first opened. The location on the Potomac River was specifically chosen for the development of a long ballistic test range on the Potomac River, required for the testing of modern, high-powered munitions.

The NSWCDD employs approximately 4,700 scientists, engineers and support personnel at the Dahlgren organization and more than 350 at NSWCDD DNA. Prior to 2007, Panama City Coastal Systems Station located at the Naval Support Activity Panama City was part of Dahlgren Division, but in 2008, it became its own division within the NAVSEA Naval Surface Warfare Center structure.

The physical base where NSWCDD is located became officially known as the Naval Support Activity Dahlgren (NSA Dahlgren) in 2003 when Naval Installations Command assumed all base operating functions, leaving NSWCDD as an installation tenant, however, the name NSWCDD or NSWC is still commonly used to refer to the base. There are a few other major tenant commands on the base such as the Joint Warfare Analysis Center and the Aegis Training and Readiness Center (ATRC) involved in the training and development for the Aegis Combat System, and training and development for other future shipboard combat systems. NSF Dahlgren was also previously home to Naval Space Surveillance System Command (NAVSPASUR) before that function was transferred to the Air Force in 2004. In 2006, the installation's name was changed to its current iteration of Naval Support Facility Dahlgren when Naval District Washington merged it and Naval Support Activity Indian Head under the combined command of Naval Support Activity South Potomac.