The World Association of Theoretical and Computational Chemists (WATOC) is a scholarly association founded in 1982 "in order to encourage the development and application of theoretical methods" in chemistry, particularly quantum chemistry and computational chemistry. It was originally called the World Association of Theoretical Organic Chemists, but was later renamed the World Association of Theoretically Oriented Chemists, and then renamed once more to the World Association of Theoretical and Computational Chemists.
WATOC organizes a triennial world congress (most recently in 2011 in Santiago de Compostela, Spain) and numerous smaller conferences on more specialized topics.
The association awards two yearly medals: the Schrödinger Medal to "the outstanding computational chemist in the world who has not previously received this award", and the Dirac Medal to "the outstanding computational chemist in the world under the age of 40".
Some of the presidents of WATOC (present and past) are Leo Radom, Paul von Rague Schleyer, H.F. Schaefer and I.G. Csizmadia.