The International Chemistry Olympiad (IChO) is an annual academic competition for high school students. It is one of the international science olympiads.
The first IChO was held in Prague, Czechoslovakia, in 1968. The event has been held every year since then, with the exception of 1971. The delegations that attended the first events were mostly countries of the former Eastern bloc and it was not until 1980, the 12th annual International Chemistry Olympiad, that the event was held outside of the bloc in Austria.