The Central Intelligence Agency (CIA; ), known informally as the Agency and historically as the company, is a civilian foreign intelligence service of the federal government of the United States, officially tasked with gathering, processing, and analyzing national security information from around the world, primarily through the use of human intelligence (HUMINT) and conducting covert action. As a principal member of the United States Intelligence Community (IC), the CIA reports to the Director of National Intelligence and is primarily focused on providing intelligence for the President and Cabinet of the United States. Following the dissolution of the Office of Strategic Services (OSS) at the end of World War II, President Harry S. Truman created the Central Intelligence Group under the direction of a Director of Central Intelligence by presidential directive on January 22, 1946, and this group was transformed into the Central Intelligence Agency by implementation of the National Security Act of 1947.

Unlike the Federal Bureau of Investigation (FBI), which is a domestic security service, the CIA has no law enforcement function and is mainly focused on overseas intelligence gathering, with only limited domestic intelligence collection. The CIA serves as the national manager for HUMINT, coordinating activities across the IC. It also carries out covert action at the behest of the President. It exerts foreign political influence through its paramilitary operations units, such as the Special Activities Center. The CIA was instrumental in establishing intelligence services in many countries, such as Germany's BND. It has also provided support to several foreign political groups and governments, including planning, coordinating, training in torture, and technical support. It was involved in many regime changes, and carrying out terrorist attacks and planned assassinations of foreign leaders.

Since 2004, the CIA is organized under the Office of the Director of National Intelligence (ODNI). Despite having had some of its powers transferred to the DNI, the CIA has grown in size as a response to the September 11 attacks. In 2013, The Washington Post reported that in the fiscal year 2010, the CIA had the largest budget of all IC agencies, exceeding previous estimates.

The CIA has increasingly expanded its role, including covert paramilitary operations. One of its largest divisions, the Information Operations Center (IOC), has officially shifted focus from counterterrorism to offensive cyber operations.

The agency has been the subject of many controversies, including human rights violations, domestic wiretapping, propaganda, and allegations of drug trafficking.