The European Atomic Energy Community (EAEC or Euratom) is an international organisation established by the Euratom Treaty on 25 March 1957 with the original purpose of creating a specialist market for nuclear power in Europe, by developing nuclear energy and distributing it to its member states while selling the surplus to non-member states.

[3][4] However, under the terms of the UK–EU Trade and Cooperation Agreement, the United Kingdom participates in Euratom as an associated state following the end of the transition period on 31 December 2020.

[6] The Soviet Union launched a propaganda campaign against Euratom, as it sought to stoke fears among Europeans that the organization would enable West Germany to develop nuclear weapons.

However, Jean Monnet, ECSC architect and President, wanted a separate community to cover nuclear power.

However, the Benelux states and Germany were also keen on creating a general single market, although it was opposed by France due to its protectionism, and Jean Monnet thought it too large and difficult a task.

Euratom would foster cooperation in the nuclear field, at the time a very popular area, and would, along with the EEC, share the Common Assembly and Court of Justice of the ECSC, but not its executives.

A report by the House of Commons Business, Energy and Industrial Strategy Committee, published in May 2017, questioned the legal necessity of leaving Euratom and called for a temporary extension of membership to allow time for new arrangements to be made.

[35] The UK-EU Trade and Cooperation Agreement, outlining the UK's relationship with the European Union from 1 January 2021, makes provision for the United Kingdom's participation "as an associated country of all parts of the Euratom programme".

[5] In the history of European regulation, Article 37 of the Euratom Treaty represents pioneering legislation concerning binding transfrontier obligations with respect to environmental impact and protection of humans.