This article investigates the relationship between populism in power and the expansion of mechanisms of direct democracy (MDDs) in Latin America. We hypothesise that the introduction of new or additional MDDs is more likely under populist than non-populist presidents due to core populist ideas. We then add a conditional explanation to this ideational argument grounded in a strategic calculus and hypothesise that the expansion of MDDs is even more likely if the political context in which populist presidents are embedded provides strategic incentives to promote MDDs. We test these hypotheses by means of logistic and Poisson regression analyses using a newly compiled data set covering information on the introduction and reform of MDDs in 18 Latin American countries from 1980 to 2018. Our results indicate that expansion of MDDs is, indeed, more likely promoted by populist presidents and that this association is conditioned by the degree of presidential approval.