My dissertation explores the ideological ties between the Spanish dictatorship (1936-1975) and the right-wing military dictatorships in Argentina and Chile during the Cold War era. It focuses on the transatlantic operations of the Opus Dei, a formal prelature of the Catholic Church originating from Nationalist Spain. During the 1960s this group propagated a distinctive post-fascist ideology of market-centered development in Latin America. My research postulates that, in turn, the Opus Dei informed Latin America's authoritarian phase of the 1960s and 1970s. More specifically, my research focuses on the Opus Dei's involvement with the design of the dictatorships of Juan Carlos Onganía in Argentina (1966) and Augusto Pinochet in Chile (1973). I illuminate how an international network of Opus Dei intellectuals helped designing the state-ideologies of these regimes, backed by a notable disciplinary and economic apparatus. Beyond analyzing its exact neoliberal philosophies, I indicate how through its cultural apparatuses and gender policies, the Opus Dei's set out to inaugurate a holistic, if not paradoxical, Catholic modernization during this period. Thus, my dissertation contributes to the emerging historiography on the Latin American Right. By presenting a clear genealogy between the preceding 1930s Hispanic fascism and the Opus Deist Cold War authoritarianism, it illuminates the sui generis quality of the Global South's counterrevolutionary ideologies. I indicate how a new generation of Latin Americans and Spaniards aimed to combat communism, but no less important, to offer a spiritually-guided path for modernity that would challenge the "materialist" ethics of the western liberal-democracies. In sum, I raise the possibility that the relative hegemonic position the Opus Dei ideology had achieved during the Cold War years impacts Latin American societies and economies until this very day.