The following is a list of the major existing intergovernmental organizations (IGOs). For a more complete listing, see the Yearbook of International Organizations, which includes 25,000 international non-governmental organizations (INGOs), excluding for-profit enterprises, about 5,000 IGOs, and lists dormant and dead organizations as well as those in operation (figures as of the 400th edition, 2012/13). A 2020 academic dataset on international organizations included 561 intergovernmental organizations between 1815 and 2015; more than one-third of those IGOs ended up defunct.

United Nations and agencies

The UN has six principal organs: The UN also includes various Funds, Programmes and specialized agencies: The UN also includes subsidiary organs:

Agricultural research organizations

Fisheries organizations

Maritime organizations

Financial, trade, and customs organizations

Regional organizations

Europe

Asia

Transcontinental

Africa

Americas

Military alliances

Cultural, ethnic, linguistic, and religious organizations

Educational organizations and universities

Law enforcement cooperation

Transport

Humanitarian organizations

Environmental organizations

Arms control

Energy organizations

Multi sector organizations

Nuclear power organizations

Sustainable energy organizations

Digital organizations

Ideological and political groupings

(disbanded)

Other

Defunct