An organization that identifies itself as international or intergovernmental, has membership from, and represents the interests of, more than one country, without regard to whether the headquarters of the organization and location of the activity are inside or outside of the United States.

An international organization, or more formally intergovernmental organization (IGO), is an organization, such as the European Community or the WTO, with sovereign states or other IGOs as members. Such organizations function according to the principles of intergovernmentalism, which means that unanimity is required. The European Union is however an exception to this rule in some areas.

International Organization is a peer-reviewed journal that covers the entire field of international affairs. Subject areas include: foreign policies, international relations, international and comparative political economy, security policies, environmental disputes and resolutions, European integration, alliance patterns and war, bargaining and conflict resolution, economic development and adjustment, and international capital movements.