The Nuclear Energy Agency (NEA) is an intergovernmental agency that is organised under the Organisation for Economic Co-operation and Development (OECD). Its mission is to "assist its member countries in maintaining and further developing ... the safe, environmentally friendly and economical use of nuclear energy for peaceful purposes". It was formed in Feburary of 1958 by the OECD. The NEA was at that time called the European Nuclear Energy Agency (ENEA), and was changed to the NEA in 1972 to refect its growing membership beyond Europe.

The NEA currently consists of 34 countries from Europe, North America and the Asia-Pacific region. In 2022, Russia's membership has been suspended due to its invasion of Ukraine.