United Nations
- United Nations Educational Scientific and Cultural Organization
- United Nations Relief and Rehabilitation Administration
- United Nations Relief and Works Agency for Palestine Refugees in the Near East
- United Nations Secretaries-General
- United Nations Security Council
- United Nations Universal Declaration of Human Rights
- Universal Postal Union
- UNO
- who
- World Bank
- World Court
- World Health Organization
- World Intellectual Property Organization
- World Meteorological Organization