Normal Science is a concept originated by Thomas Samuel Kuhn and elaborated in The Structure of Scientific Revolutions. The term refers to the routine work of scientists experimenting within a paradigm, slowly accumulating detail in accord with established broad theory, not actually challenging or attempting to test the underlying assumptions of that theory. Kuhn identified this mode of science as being a form of "puzzle-solving."

According to Kuhn, Normal science possesses a built-in mechanism that ensures the relaxation of the restrictions that bound research whenever the paradigm from which they derive ceases to function effectively. Silvio Funtowicz and Jerome Ravetz developed the concept of post-normal science.