Claude Georges Itzykson, (11 April 1938 – 22 May 1995) was a French theoretical physicist who worked in quantum field theory and statistical mechanics.

[1][2] Separated from his parents by World War II, his father was taken to a Nazi concentration camp and Itzykson is raised in a Jewish orphanage in Maisons-Laffitte.

He joined the Theoretical Physics Department of the CEA in Saclay in 1962,[1] then headed by Claude Bloch.

[2] He spent most of his career at Saclay, except for numerous visiting positions he held throughout his working life, such as at the Institute for Advanced Study, Princeton.

[2] In 1980 he published a treatise on quantum field theory with Jean-Bernard Zuber that became a staple textbook on the subject.