Matthias Ballauff (born 13 July 1952) is a German chemist and physicist, and is a professor of physics at the Free University of Berlin. His postdoctoral research and training was directed by Paul Flory. He contributed to various areas of physical chemistry, in particular to polymer science, colloidal chemistry and nanomaterials, as well as to soft matter physics. Ballauff is particularly known for having developed new catalyst materials in the form of functionalized metallic nanoparticles dispersed in liquid phase, which can greatly speed up the reaction kinetics of organic molecules.