This course provides an introduction to the main sociological theories of populism. The populist political phenomenon is analyzed from the point of view of the social dynamics of democracy and not only, as is the case with political science, from the point of view of institutional structures. The objective of this course, which is divided into lectures and seminars, is to provide the student with a sociological perspective on the transformations of democracy due to the pressure of populism. In the first part the main general theories will be analyzed (Germani, Laclau, Canovan), in the second part the contemporary theories of populism (Weyland, Mudde etc.) and in the third part the most paradigmatic cases of populism, such as Latin American, Italian, European, will be discussed.