The International Nuclear Science Olympiad (INSO) is the premier competition in nuclear science for high school students, aiming to promote scientific excellence and international cooperation in nuclear science and technology.

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

Competitors are expected to be selected from general or technical high schools in participating countries, and participants must not exceed 20 years of age by June 30 of the year the competition is held.