Jean Zinn-Justin (born 10 July 1943 in Berlin) is a French theoretical physicist.
Zinn-Justin was educated in physics (undergraduate 1964) at the École Polytechnique, and did graduate work in theoretical physics at Orsay, (Ph.D. 1968) under the supervision of Marcel Froissart.
Zinn-Justin has worked since 1965 as a theoretical and mathematical physicist at the Saclay Nuclear Research Centre (CEA), where he was head of theoretical physics in 1993−1998 .
He has made seminal contributions to the renormalizability of gauge theories.
He is a world authority on quantum field theory in particle and phase transitions in statistical physics, and, in particular, the renormalization group organizing and connecting these two areas.