An acronym for the Central Intelligence Agency of the United States of America. Although, the agency is technically headquartered in McLean, Virginia, it is referred to as "Langley", the name of the community in McLean where the agency is located. The CIA wields an enormous budget and much authority, but the details of its activities are not publicized. The CIA is said to engage in espionage and intelligence activities (HUMINT), providing the US government with information vital to the country's foreign policy and national security decisions. Its activities also include foreign counterintelligence within the United States. At times the CIA will work in cooperation with the Federal Bureau of Investigation (FBI).

Its precursor was the Office of Strategic Services (OSS) of World War II. The CIA was established by the National Security Act of 1947.