Michael Polanyi (; Hungarian: Pollacsek Mihály; 11 March 1891 – 22 February 1976) was a Hungarian-British polymath, who made important theoretical contributions to physical chemistry, economics, and philosophy. He argued that positivism supplies a false account of knowing, which if taken seriously undermines humanity's highest achievements.

His wide-ranging research in physical science included chemical kinetics, x-ray diffraction, and adsorption of gases. He pioneered the theory of fibre diffraction analysis in 1921, and the dislocation theory of plastic deformation of ductile metals and other materials in 1934. He emigrated to Germany, in 1926 becoming a chemistry professor at the Kaiser Wilhelm Institute in Berlin, and then in 1933 to England, becoming first a chemistry professor, and then a social sciences professor at the University of Manchester. Two of his pupils, and his son John Charles Polanyi won Nobel Prizes in Chemistry. In 1944 Polanyi was elected to the Royal Society.

The contributions which Polanyi made to the social sciences, for example his application of the concept of a polycentric spontaneous order to intellectual inquiry, were developed in the context of his opposition to central planning.