The article analyzes the economic entries of the main Spanish general encyclopedias of the late nineteenth and early twentieth centuries: Diccionario enciclopédico (1887–1898) and Enciclopedia universal (1908–1930). Both works include the contributions of prestigious Spanish and Latin American intellectuals, and were designed for distribution in Spain and Latin American markets. Diccionario enciclopédico was the first to introduce the “social question” in its economic entries, which were drafted by the most outstanding Spanish economists at the time. These entries were characterized by the absence of any significant mention of historicism and marginalism, which illustrates the isolationism of Spanish economists during the late nineteenth century. Enciclopedia universal, on the other hand, was not entirely drafted by academic economists. Nevertheless, its economic entries account for a complete outline of marginalism, Marxism, and historicism. Apart from the traditional goals of compiling the intellectual advances made in any area of human knowledge for educational purposes, the economic entries of both encyclopedias aimed at popularizing some kind of economic knowledge in order to prepare minds for the reception of specific doctrines and agendas: the secular social doctrine of Spanish Krausism and the religious Social Catholicism, respectively.