Italy is depicted as a populist promised land. Especially within Western Europe, Italy is an outlier in terms of support for and varieties of populist parties. Yet, common explanations of populism do not fully account for the Italian exceptionality, while single-country studies often present time-wise limited focus or anecdotical evidence. This article contributes by providing a novel interpretation of Italian populism since 1945 through a three-step process. First, the Italian populist success is theoretically linked to societal anti-parliamentarism and anti-elitism, whose roots date back to the formation of the unitary state and its institutional weakness. Second, it is argued that traditional intra-country differences in terms of voting behavior still matter when it comes to providing the opportunity structure for populist parties. Finally, a preliminary empirical analysis shows that–in line with expectations–different political traditions across the national territory are likely to determine the success of specific types of populism. The findings are relevant for the generation of new hypotheses about the societal origins of contemporary populist parties.