International Organization is a peer-reviewed academic 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.

An international organization is an organization with an international membership, scope, or presence. There are two main types:

• International nongovernmental organizations (INGOs): non-governmental organizations (NGOs) that operate internationally. These include international non-profit organizations and worldwide companies such as the World Organization of the Scout Movement, International Committee of the Red Cross and Médecins Sans Frontières.
• Intergovernmental organizations, also known as international governmental organizations (IGOs): the type of organization most closely associated with the term 'international organization', these are organizations that are made up primarily of sovereign states (referred to as member states). Notable examples include the United Nations (UN), Organisation for Economic Co-operation and Development (OECD), Organization for Security and Co-operation in Europe (OSCE), Council of Europe (CoE), and World Trade Organization (WTO). The UN has used the term "intergovernmental organization" instead of "international organization" for clarity.