John Ross (October 2, 1926 – February 18, 2017) was a scientist in physical chemistry and the Camille and Henry Dreyfus Professor of Chemistry at Stanford University. Unraveling the mechanisms of complex chemical reactions, Ross opened new avenues in physical chemistry through the development of groundbreaking methods to study complex reactions within intact systems. His theoretical and experimental studies in statistical mechanics and chemical kinetics proved new means to reveal details of biochemical reactions taking place far from equilibrium and involving many chemical species.