Jean Louis, baron Bourgain (French: [buʁɡɛ̃]; (1954-02-28)28 February 1954 – (2018-12-22)22 December 2018) was a Belgian mathematician.

He was awarded the Fields Medal in 1994 in recognition of his work on several core topics of mathematical analysis such as the geometry of Banach spaces, harmonic analysis, ergodic theory and nonlinear partial differential equations from mathematical physics.

He was a faculty member at the University of Illinois Urbana-Champaign and, from 1985 until 1995, professor at Institut des Hautes Études Scientifiques at Bures-sur-Yvette in France, at the Institute for Advanced Study in Princeton, New Jersey from 1994 until 2018.

He formulated what became known as the Bourgain slicing problem in high-dimensional convex geometry.

[8] Together with Ciprian Demeter and Larry Guth, he proved Vinogradov's mean-value theorem in 2015.

In 2009 Bourgain was elected a foreign member of the Royal Swedish Academy of Sciences.

[11] In 2012, he and Terence Tao received the Crafoord Prize in Mathematics from the Royal Swedish Academy of Sciences.