Krzysztof Matyjaszewski (; ; born April 8, 1950) is a Polish-American chemist. He is the J.C. Warner Professor of the Natural Sciences at the Carnegie Mellon University Matyjaszewski is best known for the discovery of atom transfer radical polymerization (ATRP), a novel method of polymer synthesis that has revolutionized the way macromolecules are made. In 2011 he was a co-winner of the prestigious Wolf Prize in Chemistry.