Member states

A member state is a state that is a member of an international organization, federation, or confederation.

Since the World Trade Organization (WTO) and the International Monetary Fund (IMF) include some members that are not sovereign states, neither organization ever speaks of "member states". The WTO has simply "members" (see WTO members), and the IMF refers to its members as "member countries".

The oldest global member state based organization is the International Telecommunication Union, which joined the United Nations System as a specialized agency after the creation of the UN.

Worldwide

Member states of the United Nations | 193
Member states of the International Telecommunication Union | 193
Member states of UNESCO | 195
Interpol § Members | 190
Member states of the World Intellectual Property Organization | 184
Member states of the World Sports Alliance | 49
Member states of the League of Nations
Member states of the Venice Commission | 58
Member states of the World Customs Organization | 173 sovereign states, 4 customs territories and one customs union
Member states of the World Trade Organization | 166
International Hydrographic Organization § Member countries
International Centre for the Study of the Preservation and Restoration of Cultural Property § Member states
Alliance of Small Island States § Member states | 39
Intersputnik § Member states
World Health Organization | 194

Worldwide - language related

Member states of the Arab League | 22
Member states of the Dutch Language Union | 3
Member states of the Commonwealth of Nations | 56
Member states of the Latin Union | 36
Member states of the Community of Portuguese Language Countries | 8
Member states of the International Organization of the Francophonie
Member states of the Organization of Ibero-American States | 24

Worldwide - religion related

Member states of the Organisation of Islamic Cooperation | 57

Worldwide - commodity related

Member states of the International Atomic Energy Agency | 167
Member states of OPEC | 12
Member states of CIP | 14
Member states of the Organisation for the Prohibition of Chemical Weapons | 195+

Restricted to a continent or larger region

	Count	Region	Note
Member states of the Council of Europe	47	Europe
Member state of the European Union	27	Europe
Member states of the European Economic Area	30	Europe	EU + Iceland, Liechtenstein, Norway
Member states of the European Environment Agency	32	Europe	EU + Iceland, Liechtenstein, Norway, Switzerland, Turkey
Member states of the European Aviation Safety Agency	31	Europe	EU + Iceland, Liechtenstein, Norway, Switzerland
Member states of the European Union Customs Union	31	Europe	EU + Turkey, San Marino, Andorra, Monaco
Member states of the Eurozone	21	Europe
Member states of the European Free Trade Association	4	Europe
Member states of the Organization of the Black Sea Economic Cooperation		Europe
Central European Free Trade Agreement		Europe
Member states of the European Southern Observatory	15	Europe
Nordic Council#Members	5	Europe
Council of the Baltic Sea States#Member states		Europe
Western European and Others Group#WEOG Member States		Europe
Eastern European Group#Members		Europe
European Space Agency	22	Europe	1 Associate Canada
Member states of the Organization of American States	35	America	+75 Permanent Observers
Member states of the Union of South American Nations	12	America
Member states of Mercosur	5	America
Member states of the Bolivarian Alliance for the Americas	8	America
Member states of the Caribbean Community	15	America
Association of Caribbean States#Member states	25	America
Caribbean Meteorological Organisation		America
Inter-American Development Bank#Member states	48	America
Member states of the African Union	55	Africa	9 observer states + 1 suspended
Southern African Development Community	14	Africa
Member states of the Association of Southeast Asian Nations	11	Asia
Member states of the Cooperation Council for the Arab States of the Gulf	6	Asia
Member states of Shanghai Cooperation Organisation	6	Asia	+5 observers
United Nations Economic and Social Commission for Western Asia#Member states	14	Asia
Economic Cooperation Organization#Member states	10	Asia
Arctic Council#Member states	8	Arctic	13 observers

Other

Member states of the Commonwealth of Independent States | 9 + 2 unofficial participants (Turkmenistan and Ukraine)

Military

Member states of NATO | 32

In history:

Warsaw Pact § Members
Central Powers § Member states