The United Kingdom has been a charter member of the United Nations along with the United States, France, the Soviet Union and the Republic of China since 1946. The United Kingdom is also one of the permanent members of the United Nations Security Council and is the fourth largest provider of assessed financial contributions to the UN's peacekeeping operations, providing 6.604 percent of the United Nations Budget.

English is one of the two working languages used in the United Nations Secretariat and the United Kingdom is home to the International Maritime Organization, whose head offices are in Embankment, London.

The United Nations Association of the United Kingdom (UNA-UK) was established to provide independent research, information and analysis on the UN and advocates government support for the United Nations. The UN Association of the UK aims to:

Educate young people about the United Nations
Raise awareness of the United Nations
Campaign for UK support of the United Nations
Promote international development, human rights, peace and security
Stimulate debate and thought on how to advance the United Nations goals

United Nations Association of the UK has offices in SW London.

The United Kingdom has Permanent Missions to the United Nations with offices in New York and Geneva. The Permanent Missions to the UN represent the United Kingdom during negotiations and ensure that Britain's view and interests are taken into account.

In addition to being a member of the United Nations, the United Kingdom is also a member of the European Union, the Commonwealth of Nations, NATO, the World Trade Organization, G7, G8 and G20, the Council of Europe and the OECD.