[7] Witten was born on August 26, 1951, in Baltimore, Maryland, to a Jewish family,[8] as the eldest of four children.

[13] Witten attended the Park School of Baltimore (class of 1968), and received his Bachelor of Arts degree with a major in history and minor in linguistics from Brandeis University in 1971.

[18] He returned to academia, enrolling in applied mathematics at Princeton University in 1973, then shifting departments and receiving a PhD in physics in 1976 and completing a dissertation, "Some problems in the short distance analysis of gauge theories", under the supervision of David Gross.

[24] Another result for which Witten was awarded the Fields Medal was his proof in 1981 of the positive energy theorem in general relativity.

[25] This theorem asserts that (under appropriate assumptions) the total energy of a gravitating system is always positive and can be zero only if the geometry of spacetime is that of flat Minkowski space.

[28] A third area mentioned in Atiyah's address is Witten's work relating supersymmetry and Morse theory,[29] a branch of mathematics that studies the topology of manifolds using the concept of a differentiable function.

Witten's work gave a physical proof of a classical result, the Morse inequalities, by interpreting the theory in terms of supersymmetric quantum mechanics.

[34] In collaboration with Nathan Seiberg, Witten established several powerful results in quantum field theories.

[37] With Anton Kapustin, Witten has made deep mathematical connections between S-duality of gauge theories and the geometric Langlands correspondence.

[38] Partly in collaboration with Seiberg, one of his recent interests includes aspects of field theoretical description of topological phases in condensed matter and non-supersymmetric dualities in field theories that, among other things, are of high relevance in condensed matter theory.

[40] In particular, Witten is known for collaborating with Ruth Britto on a method calculating scattering amplitudes known as the BCFW recursion relations.

[50] In an informal poll at a 1990 cosmology conference, Witten received the largest number of mentions as "the smartest living physicist".

[55] He supports the two-state solution and advocates a boycott of Israeli institutions and economic activity beyond its 1967 borders, though not of Israel itself.