As of 2026-10-12, American Association for the Advancement of Science tops the list with 120,000 members.
- #1 American Association for the Advancement of Science — 120,000 members
international non-profit organization promoting science
The American Association for the Advancement of Science (AAAS) is a United States–based international nonprofit with the stated mission of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsibility, and supporting scientific education and science outreach for the betterment of all humanity. AAAS was the first permanent organization established to promote science and engineering nationally and to represent the interests of American researchers... Read more on Wikipedia.
Wikidata - #2 Industrial Workers of the World — 12,300 members
international union founded in 1905
The Industrial Workers of the World (IWW), whose members are nicknamed "Wobblies", is an international labor union founded in Chicago, Illinois, United States, in 1905. Its ideology combines general unionism with industrial unionism, as it is a general union, subdivided between the various industries which employ its members. The philosophy and tactics of the IWW are described as "revolutionary industrial unionism", with ties to socialist, syndicalist, and anarchist labor movements. Read more on Wikipedia.
Wikidata - #3 Interpol — 196 members
International Criminal Police Organization (founded 1923)
The International Criminal Police Organization – INTERPOL (ICPO–INTERPOL), commonly known as Interpol, is an international organization that facilitates worldwide police cooperation and crime control. It is the world's largest international police organization. It is headquartered in Lyon, France, with seven regional bureaus worldwide and a National Central Bureau in each of its 196 member states. Read more on Wikipedia.
Wikidata - #4 United Nations — 193 members
global international and intergovernmental organization
The United Nations (UN) is an international intergovernmental organization established by the signing of the Charter of the United Nations on 26 June 1945 with the articulated mission of maintaining international peace and security, to develop friendly relations among states, to promote international cooperation, and to serve as a centre for harmonizing the actions of states in achieving those goals. Read more on Wikipedia.
Wikidata - #5 World Trade Organization — 164 members
intergovernmental organization that intends to supervise and liberalize international trade
The World Trade Organization (WTO) is an intergovernmental organization that regulates and facilitates international trade. Established on 1 January 1995, pursuant to the 1994 Marrakesh Agreement, it succeeded the General Agreement on Tariffs and Trade (GATT), which was created in 1948. As the world's largest international economic organization, the WTO has 166 members, representing over 98% of global trade and global GDP. It is headquartered in Geneva, Switzerland. Read more on Wikipedia.
Wikidata - #6 Association of World Election Bodies — 119 members
organization
The Association of World Election Bodies, commonly referred to as ‘A-WEB’, was established on October 14, 2013 in Song-do, South Korea. A-WEB is the first global organization of election management bodies, and the membership currently consists of 118 EMBs as members and 20 Regional associations as associate members. Under the slogan of ‘Democracy to Grow for All Worldwide,’ the A-WEB Secretariat provides training programs for election officials of member nations and undertakes country... Read more on Wikipedia.
Wikidata - #7 Club of Rome — 100 members
political and economic think tank
The Club of Rome is a nonprofit, informal organization of intellectuals and business leaders whose goal is a critical discussion of pressing global issues. The Club of Rome was founded in 1968 at Accademia dei Lincei in Rome, Italy. At least until the early 2000s, the 'main club' has allegedly been limited to one hundred members, often selected from current and former heads of state and government, UN administrators, high-level politicians, diplomats, scientists, economists, and business... Read more on Wikipedia.
Wikidata - #8 Worldskills International — 82 members
international governing body of WorldSkills
source Wikidata - #9 Association of North East Asia Regional Goverments — 79 members source Wikidata
- #10 Women's International Zionist Organization — 67 members
organization
The Women's International Zionist Organization is a volunteer organization dedicated to social welfare in all sectors of Israeli society, the advancement of the status of women, and Jewish education in Israel and the diaspora. Read more on Wikipedia.
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