Ronald C. D. Breslow (born March 14, 1931) is an American chemist from Rahway, New Jersey. He is currently University Professor at Columbia University, where he is based in the Department of Chemistry and affiliated with the Departments of Biological Sciences and Pharmacology; he has also been on the faculty of its Department of Chemical Engineering. He has taught at Columbia since 1956 and is a former chair of the university's chemistry department.He is interested in the design and synthesis of new molecules with interesting properties, and the study of these properties. Examples include the cyclopropenyl cation, the simplest aromatic system and the first aromatic compound prepared with other than six electrons in a ring. He won American Institute of Chemists Gold Medal in 2014.