John Benjamin Kogut (6 March 1945) is an American theoretical physicist, specializing in high energy physics.
Kogut received in 1971 his PhD from Stanford University under James Bjorken with thesis Quantum electrodynamics at infinite momentum: applications to high energy scattering.
For 27 years he was on the physics faculty of the Loomis Laboratory at the University of Illinois, Urbana-Champaign, retiring in 2005 as professor emeritus.
Kogut is known for the Kogut–Susskind fermion and his collaboration with Leonard Susskind on the Hamiltonian formulation of Kenneth G. Wilson's lattice gauge theory.
Kogut played a leading role in opposing the Strategic Defense Initiative (aka "Star Wars") in the 1980s.