The 820th Base Defense Group is a United States Air Force unit responsible for providing defense and security at various air bases. Established in 1946, the group operates under Air Combat Command’s 821st Contingency Action Group (CAG), which provides rapid response force protection to U.S. military installations worldwide. The 820th BDG’s primary role includes threat detection, force protection operations, security coordination, and emergency response. They work closely with other military and civilian agencies to ensure the safety and readiness of air bases under their jurisdiction. The group is headquartered at Joint Base Langley-Eustis, Virginia.