American mathematician who was awarded the 1994 Nobel Prize for Economics for his landmark work, first begun in the 1950s, on the mathematics of game theory. He shared the Nobel Prize with the Hungarian American economist John C. Harsanyi (Harsanyi, John C.) and German mathematician Reinhard Selten (Selten, Reinhard).

In 1948 Nash received bachelor's and master's degrees in mathematics from the Carnegie Institute of Technology (now Carnegie-Mellon University) in Pittsburgh, Pennsylvania. Two years later, at age 22, he completed his doctorate at Princeton University, publishing his influential thesis “Non-cooperative Games” in the journal Annals of Mathematics. He joined the faculty of the Massachusetts Institute of Technology in 1951 but resigned in the late 1950s after bouts of mental illness. He then began an informal association with Princeton.

Nash established the mathematical principles of game theory, a branch of mathematics that examines the rivalries among competitors with mixed interests. Known as the Nash solution or the Nash equilibrium, his theory attempted to explain the dynamics of threat and action among competitors. Despite its practical limitations, the Nash solution was widely applied by business strategists.

A film version of Nash's life, A Beautiful Mind (2001), based on Sylvia Nasar's 1998 biography of the same name, won an Academy Award for best picture. It portrays Nash's long struggle with schizophrenia.