List of counterintelligence organizations
Counterintelligence organizations and agencies attempt to prevent foreign intelligence organizations from successfully gathering and collecting intelligence against the governments they serve.
 Active counterintelligence organizations
- Belgian State Security Service — in Dutch, Staatsveiligheid (SV); in French, Sûreté de l'État (SE)
- An Garda Siochana (National Police Service) — under the Deputy Commissioner for Operations are the Special Services, Security & Intelligence, Special Branch C3 Section (dealing with terrorism and subversion)
- the Netherlands
- United Kingdom
- Security Service, commonly known as MI5
- Royal Air Force Police Special Investigations and Intelligence Branch
- United States
- United States Army Intelligence CI Special Agents (USAI)
- Army Intelligence and Security Command (INSCOM)
- Air Force Office of Special Investigations (AFOSI)
- DIA's Defense Counterintelligence and Human Intelligence Center (DCHC)
- Defense Criminal Investigative Service (DCIS)
- Diplomatic Security Service (DSS), U.S. Department of State (DS/ICI/CI)
- Federal Bureau of Investigation Foreign Counterintelligence Program
- Naval Criminal Investigative Service (NCIS, formerly NIS)
- Office of the National Counterintelligence Executive (NCIX)
- Central Intelligence Agency (CIA)
 Defunct counterintelligence organizations
These organizations are now defunct, possibly absorbed by a successor organization.
- Nazi Germany
- Wojskowe Służby Informacyjne (WSI) — dissolved in 2006 for having been involved in illegal activities
- Soviet Union and Imperial Russia
- Committee for State Security (KGB) — previously MGB, NKVD, OGPU, Cheka, and, during imperial times, Okhrana
- United States
- "Overview of ASIS's purpose". ASIS. Retrieved 7 October 2012.
- "CFNCIU". Retrieved 2011-04-15.
- "Czech Intelligence Service". Retrieved 2007-11-08.
- "Hellenic National Intelligence Service". Retrieved 2007-11-08.
- Nomikos, John M. (Winter 2004). "Greek Intelligence Service and Post 9/11 Challenges" (PDF). The Journal of Intelligence History 4 (2). Retrieved 2007-11-08.
- "The crisis of the Hungarian intelligence services". November 8, 2007. Retrieved 2007-11-08.
- "Ireland: Intelligence". Retrieved 2007-11-08.
- "Public Security Investigation Agency". Retrieved 2007-11-08.
- "Kenyan National Security Intelligence Service". Retrieved 2007-11-08.
- Hunt, Emily (February 6, 2006). "Can al-Qaeda's Lebanese Expansion Be Stopped?". Washington Institute for Near East Policy. Retrieved 2007-11-06.
- "Switzerland: Intelligence Agencies". Retrieved 2007-11-08.
- "Erdoğan resists calls for northern Iraq incursion". USA-Turkish Times. Retrieved 2007-11-07.