The article is devoted to the study of the emergence and development of populism in the political struggle of the late Roman Republic. It focuses on the purely Roman nature of this phenomenon, which distinguishes it from ancient Greek demagogy, and highlights the basic principles and goals to which populist politicians appealed. The authors show that in its original meaning populism was a way of ensuring the participation of the people in politics. Despite all the ambiguity of this phenomenon, a conclusion is made about the objective regularity of the emergence of populism and about its high significance in the conditions of the social, economic and political transformation of the late Roman Republic. In addition, populism can be viewed as a marker of the existence of democratic politics, which presupposes the presence of civic virtues, both among citizens and among politicians, as well as the active participation of the people in political life.