The International Nuclear Science Olympiad (INSO) is the premier nuclear science competition for secondary school students. It aims to promote scientific excellence and international collaboration in nuclear science and technology.

Organized under the auspices of the International Atomic Energy Agency (IAEA), in cooperation with host governments and partner institutions, the INSO is modeled after other international science Olympiads, such as the International Physics Olympiad (IPhO) and the International Chemistry Olympiad (IChO), with a particular focus on nuclear science and its peaceful applications.

Participants are expected to be selected from general or technical secondary schools in participating countries, and must be no older than 20 years of age on June 30 of the competition year.