Here are all the Inter-governmental Organizations with their Headquarters and Current Chiefs.
Important (51)
| Organization Name | Year of Formation | Headquarters | Name of Current Chief |
| United Nations | |||
| UN General Assembly | 1945 | New York | Peter Thomson (Fiji) |
| UN Security Council | 1945 | ..Changed Monthly.. | |
| UN Economic and Social Council | 1945 | Frederick Musiiwa Makamure Shava | |
| UN Secretariat | 1945 | António Guterres (Portugal) | |
| International Court of Justice | 1945 | The Hague (Netherlands) | Ronny Abraham (France) |
| Food and Agriculture Organization | 1945 | Rome (Italy) | Jose Graziano da Silva |
| International Labour Organization | 1919 | Geneva (Switzerland) | Guy Ryder |
| International Maritime Organization | 1959 | London (UK) | Ki Tack Lim |
| United Nations Children's Fund (UNICEF) | 1946 | New York (USA) | Anthony Lake |
| United Nations Educational, Scientific and Cultural Organization (UNESCO) | 1945 | Paris (France) | Irina Bokova |
| United Nations Environment Programme (UNEP) | 1972 | Nairobi (Kenya) | Achim Steiner |
| World Health Organization | 1948 | Geneva (Switzerland) | Margaret Chan |
| World Intellectual Property Organization | 1967 | Geneva (Switzerland) | Francis Gurry |
| World Food Programme | 1961 | Rome (Italy) | David Beasley |
| World Tourism Organization | 1957 | Madrid (Spain) | Taleb Rifai |
| United Nations Development Programme | 1965 | New York (USA) | Helen Clark |
| United Nations Capital Development Fund | 1966 | New York (USA) | Judith Karl (Executive Secretary) |
| United Nations Industrial Development Organization | 1966 | Vienna (Austria) | Li Yong |
| Environmental | |||
| International Union for Conservation of Nature | 1948 | Gland, Switzerland | Inger Andersen (Director General, Zhang Xinsheng (President) |
| Arms Control | |||
| Organisation for the Prohibition of Chemical Weapons | 1997 | The Hague, Netherlands | Ahmet Uzumcu |
| Energy | |||
| International Energy Agency | 1974 | Paris (France) | Fatih Birol |
| International Renewable Energy Agency | 2009 | Masdar City (United Arab Emirates) | Adnan Amin |
| Nuclear Energy Agency | 1958 | Paris (France) | William D. Magwood, IV |
| International Atomic Energy Agency | 1957 | Vienna (Austria) | Yukiya Amano |
| Economic Institutions | |||
| International Monetary Fund | 1945 | Washington, D.C.( United States) | Christine Lagarde |
| Asian Development Bank | 1966 | Manila (Philippines) | Takehiko Nakao |
| International Fund for Agricultural Development | 1977 | Rome (Italy) | Kanayo F. Nwanze |
| African Development Bank | 1964 | Ivory Coast | Akinwumi Adesina |
| Bank for International Settlements | 1930 | Basel, Switzerland | Jaime Caruana |
| Organisation for Economic Co-operation and Development (OECD) | 1961 | Paris (France) | Jose Angel Gurria |
| Organization of the Petroleum Exporting Countries (OPEC) | 1960 (Effective from 1961) | Vienna (Austria) | President - Diezani Alison-Madueke,Secretary General - Abdallah el-Badri |
| European Central Bank | 1998 | Frankfurt (Germany) | Mario Draghi |
| Green Climate Fund | 2010 | Incheon, South Korea | Howard Bamsey |
| World Bank Group | |||
| International Bank for Reconstruction and Development | 1945 | Washington, D.C. (United States) | Jim Yong Kim |
| International Development Association | 1960 | Jim Yong Kim | |
| International Finance Corporation | 1956 | Philippe Le Houérou | |
| Multilateral Investment Guarantee Agency | 1988 | Keiko Honda | |
| International Centre for Settlement of Investment Disputes | 1965 | Meg Kinnear | |
| Miscellaneous | |||
| World Customs Organization | 1952 | Brussels (Belgium) | Kunio Mikuriya |
| World Trade Organization | 1995 | Geneva (Switzerland) | Roberto Azevêdo |
| International Criminal Court | 2002 (Rome Statute was adopted in 1998 ) | The Hague (Netherlands) | Silvia Fernández de Gurmendi |
| European Commission | 1958 | Jean-Claude Juncker | |
| European Parliament | 1952 | Martin Schulz | |
| European Council | 1961 | Donald Tusk | |
| Council of Europe | 1949 | Strasbourg (France) | Thorbjorn Jagland |
| European Organization for Nuclear Research (CERN) | 1954 | Meyrin (Switzerland) | Fabiola Gianotti |
| European Space Agency | 1975 | Paris (France) | Jean-Jacques Dordain |
| Association of Southeast Asian Nations (ASEAN) | 1967 | Jakarta (Indonesia) | Le Luong Minh |
| South Asian Association for Regional Cooperation (SAARC) | 1985 | Kathmandu (Nepal) | Arjun Bahadur Thapa |
| North Atlantic Treaty Organization (NATO) | 1949 | Brussels (Belgium) | Jens Stoltenberg |
| Asia-Pacific Economic Cooperation | 1989 | Singapore | Alan Bollard |
| African Union Commission | Nkosazana Dlamini-Zuma | ||
| African Union | 2001 | Addis Ababa (Ethiopia) | Roger Nkodo Dang |
Semi-Important (34)
| Organization Name | Year of Formation | Headquarters | Name of Current Chief |
| United Nations | |||
| United Nations Development Fund for Women | 1976 | New York (USA) | Inés Alberdi |
| United Nations High Commissioner for Refugees | 1950 | Geneva ( Switzerland) | Filippo Grandi |
| Joint United Nations Programme on HIV/AIDS | 1994 | Geneva ( Switzerland) | Michel Sidibé |
| United Nations Population Fund | 1969 | New York (USA) | Babatunde Osotimehin |
| United Nations Human Settlements Programme | 1978 | Nairobi (Kenya) | Joan Clos |
| United Nations Volunteers | 1970 | Bonn (Germany) | Richard Dictus |
| United Nations Entity for Gender Equality and the Empowerment of Women | 2010 | New York (USA) | Phumzile Mlambo-Ngcuka |
| United Nations University | 1973 | Japan | David M. Malone |
| Environmental | |||
| World Wide Fund For Nature | 1961 | Gland, Switzerland | Yolanda Kakabadse (President) Marco Lambertini (Director General) |
| Intergovernmental Panel on Climate Change | 1988 | Hoesung Lee | |
| Global Environment Facility | 1991 | Washington (USA) | Naoko Ishii |
| Migration | |||
| International Organization for Migration | 1951 | Geneva, Switzerland | William Lacy Swing |
| Maritime | |||
| International Hydrographic Organization | 1921 | Monaco | Robert Ward (President) |
| Arms Control | |||
| Nuclear Suppliers Group | 1974 | Argentina (Curent Chair) | |
| Organization for Security and Co-operation in Europe | 1973 | Vienna (Austria) | Lamberto Zannier |
| Comprehensive Nuclear-Test-Ban Treaty Organization | Vienna, Austria | ||
| Fisheries | |||
| International Whaling Commission | 1946 | Impington (England) | |
| International Seabed Authority | 1994 | Kingston (Jamaica) | |
| Economic Institutions | |||
| International Bureau of Weights and Measures | 1875 | Sevres (France) | M.J.T. Milton |
| African Development Bank | 1964 | Ivory Coast | Akinwumi Adesina |
| Bank for International Settlements | 1930 | Basel, Switzerland | Jaime Caruana |
| Nordic Investment Bank | 1976 | Helsinki (Finland) | |
| Islamic Development Bank and Organisation of Islamic Cooperation | 1975 | Jeddah(Saudi Arabia) | Ahmad Mohamed Ali Al-Madani |
| Miscellaneous | |||
| Energy Community | 2006 | Vienna (Austria) | Janez Kopac |
| European Science Foundation | 1974 | Strasbourg, France | Par Omling |
| European Southern Observatory | 1962 | Garching (Germany) | Tim de Zeeuw |
| Collective Security Treaty Organization | 1992 (as Collective Security Treaty), 2002 (as Collective Security Treaty Organization) | Moscow (Russia) | Nikolai Bordyuzha |
| Economic Cooperation Organization | 1985 | Tehran (Iran) | Halil Ibrahim Akca |
| Union of South American Nations (UNASUR) | 2008 | President - Nicolas Maduro, Secretary General - Ernesto Samper | |
| Central American Parliament | 1991 | Guatemala | Jose Antonio Alvarado Correa |
| Commonwealth of Nations | 1949 | UK | SG - Baroness Scotland of Asthal, Chairperson-in-Office - Joseph Muscat |
| Arab League | 1945 | Cairo (Egypt) | Arab League Secretariat - Ahmed Aboul Gheit, Arab Parliament - Ali Al-Daqbaashi |
Regular (21)
| Organization Name | Headquarters | Name of Current Chief |
| Migration | ||
| International Centre for Migration Policy Development | Vienna (Austria) | Peter Widermann |
| Maritime | ||
| Antarctic Treaty Secretariat | Buenos Aires, Argentina | |
| International Council for the Exploration of the Sea | Copenhagen, Denmark | |
| Fisheries | ||
| Asia-Pacific Fishery Commission | Thailand | |
| Indian Ocean Tuna Commission | Victoria (Seychelles) | |
| Inter-American Tropical Tuna Commission | California (USA) | |
| Northwest Atlantic Fisheries Organization | Canada | |
| North Atlantic Salmon Conservation Organization | UK | |
| Pacific Salmon Commission | Columbia | Susan Farlinger |
| Southeast Asian Fisheries Development Center | Thailand | |
| Western and Central Pacific Fisheries Commission | USA | Charles Karnella |
| Energy / Nuclear Energy | ||
| International Institute for Applied Systems Analysis | Vienna (Austria) | |
| Miscellaneous | ||
| European Free Trade Association | Geneva (Switzerland) | Kristinn F. Arnason |
| European Patent Organisation | Munich (Germany) | |
| Council of the Baltic Sea States | Stockholm (Sweden) | Jan Lundin |
| Southern African Development Community | Gaborone (Botswana) | |
| Economic Community of West African States | John Dramani Mahama | |
| Organization of American States | Washington, D.C. | José Miguel Insulza |
| Caribbean Community | Georgetown (Guyana) | Secretary-General - Irwin LaRocque, Chairman Gaston Browne |
| Association of Caribbean States | Port-of-Spain (Trinidad) | Alfonso Munera Cavadia |
| Organisation of Eastern Caribbean States | Saint Lucia | Chairman - Roosevelt Skerrit, Director General - Didacus Jules |