Fort Detrick is a United States Army medical installation located in Frederick, Maryland. It is home to the United States Army Medical Research and Materiel Command (MRMC), the National Cancer Institute (NCI), and the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID).

Some conspiracy theorists, notably Jakob Segal, claim that Fort Detrick was the site where the United States government invented the HIV virus.

Fort Detrick was the site of biological warfare research and there is a building on the base which was sealed in plastics after an accidental release of anthrax.