The following is a list of international organizations and their members–

Organisation Members Member Countries
Association of Southeast Asian Nations (ASEAN) 10 Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam
North American Free Trade Agreement (NAFTA) 3 Canada, Mexico and United States
Asia-Pacific Economic Cooperation (APEC) 21 Australia, Brunei Darussalam, Canada, Indonesia, Japan, South Korea, Malaysia, New Zealand, Philippines, Singapore, Thailand, United States, Taiwan, Hong Kong, China, Mexico, Papua New Guinea, Chile, Peru, Russia and Vietnam
European Union (EU) 28 Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and United Kingdom
Mercosur 5 Argentina, Brazil, Paraguay, Uruguay and Venezuela
Organization of the Petroleum Exporting Countries (OPEC) 12 Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates and Venezuela
South Asian Association for Regional Cooperation (SAARC) 8 Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka
Group of 15 (G-15) 19 Algeria, Argentina, Brazil, Chile, Egypt, India, Indonesia, Iran, Jamaica, Kenya, Malaysia, Mexico, Nigeria, Senegal, Sri Lanka, Venezuela and Zimbabwe
Organisation for Economic Co-operation and Development (OECD) 29 Australia, Austria, Belgium, Canada, Chile, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Japan, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland Switzerland, Turkey, United Kingdom and United States
Asia-Europe Meeting (ASEM) 53 Australia, Austria, Bangladesh, Belgium, Brunei Darussalam, Bulgaria, Cambodia, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, European Union, Finland, France, Germany, Greece, Hungary, India, Indonesia, Ireland, Italy, Japan, Kazakhstan, Korea, Lao PDR, Latvia, Lithuania, Luxembourg, Malaysia, Malta, Mongolia, Myanmar, Netherlands, New Zealand, Norway, Pakistan, Philippines, Poland, Portugal, Romania, Russian Federation, Singapore, Slovakia, Slovenia, Spain, Sweden, Switzerland, Thailand, United Kingdom and Viet Nam
Asian Clearing Union (ACU) 9 Bangladesh, Bhutan, India, Iran, Maldives, Myanmar, Nepal, Pakistan and Sri Lanka
United Nations (UN) 193 Timor-Leste (191st), Montenegro (192nd) and South Sudan (193rd)
South Asian Free Trade Area (SAFTA) 8 Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka
World Trade Organization (WTO) 160 160 members since 26 June 2014
Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) 7 Bangladesh, Bhutan, Myanmar, India, Nepal, Sri Lanka and Thailand
Group of 8 (G-8) 8 Canada, France, Germany, Italy, Japan, Russia (Suspended), United Kingdom, United States and European Union
D-8 Organization for Economic Cooperation 8 Bangladesh, Egypt, Indonesia, Iran, Malaysia, Nigeria, Pakistan and Turkey
Group of Twenty (G-20 or G20) 20 Argentina, Australia, Brazil, Canada, China, European Union, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, United Kingdom and UnitedStates
Shanghai Cooperation Organisation (SCO) 6 China, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan
Benelux 3 Belgium, Netherlands and Luxembourg
European Economic Community (EEC) 12 Belgium, Denmark, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain and United Kingdom
Techno-Economic Approach for Africa–India Movement (TEAM–9) 9 Burkina Faso, Chad, Cote D’Ivoire, Equatorial Guinea, Ghana, Guinea Bissau, Mali, Senegal and India
Conference on Interaction and Confidence-Building Measures in Asia (CICA) 26 Afghanistan, Azerbaijan, Bahrain, Bangladesh, Cambodia, China, Egypt, India, Iran, Iraq, Israel, Jordan, Kazakhstan, Kyrgyzstan, South Korea, Mongolia, Pakistan, Palestine, Qatar, Russia, Tajikistan, Thailand, Turkey, United Arab Emirates, Uzbekistan and Vietnam
IBSA 3 India, Brazil and South Africa
Indian-Ocean Rim Association (IORC) 20 Australia, Bangladesh, Comoros, India, Indonesia, Iran, Kenya, Madagascar, Malaysia, Mauritius, Mozambique, Oman, Seychelles, Singapore, South Africa, Sri Lanka, Tanzania, Thailand, United Arab Emirates and Yemen
Commonwealth 53 53 member states that were mostly territories of the former British Empire
North Atlantic Treaty Organization (NATO) 28 Albania, Belgium, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, United Kingdom and United States
Arab League 22 Algeria, Bahrain, Comoros, Djibouti, Egypt, Iraq, Jordan, Kuwait, Lebanon, Libya, Mauritania, Morocco, Oman, Palestine, Qatar, Saudi Arabia, Somalia, Sudan, Syrian National Coalition, Tunisia, United Arab Emirates and Yemen
Organization of Arab Petroleum Exporting Countries (OAPEC) 10

Saudi Arabia, Algeria, Bahrain, Egypt, United Arab Emirates, Iraq, Kuwait, Libya, Qatar and Syria

Commonwealth of Independent States (CIS) 12 Azerbaijan, Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Turkmenistan, Uzbekistan and Ukraine