Stanislas Leibler is a physicist whose research focuses on the quantitative description of living matter. In particular, he made contributions towards the quantitative description of cellular assembly, biochemical and synthetic genetic networks and the ecology of microbial populations. Leibler was born in Poland and after four years of undergraduate studies moved to France, where he completed his education and he received a Ph.D. in theoretical physics from University of Paris XI in 1984. Following a postdoctoral appointment at Cornell University, he became a tenured researcher in the Theoretical Physics Department of the Saclay Research Center in France. In 1992 he joined the faculty of Princeton University, where he was a professor in the Departments of Physics and Molecular Biology. In 2001, after one year as a Howard Hughes Medical Institute investigator in Princeton, Leibler moved his laboratory to the Rockefeller University. At present he splits his time between Rockefeller and the Institute for Advanced Study in Princeton, whose faculty he joined in 2009. He is a fellow of the American Physical Society and a member of the National Academy of Sciences.