Although interdisciplinary approaches to education are found throughout the West, interdisciplinarity is not everywhere conceived and implemented the same way. Adopting a socio-historical perspective, this article presents two conceptions of interdisciplinarity in primary and middle school education (though the conceptions are apparent at other levels, also), one Anglo-Saxon and American, based on the notion of curriculum, the other French and European, based on the notion of didactics. The Anglo-Saxon and American conception promotes a functional, pragmatic and utilitarian reading of interdisciplinarity that translates, in education, into a greater focus on pedagogical methods in order to promote learning processes and to address societal problems, questions, and phenomena related to the real world. The Francophone European conception for its part puts greater emphasis on the question of epistemology, on the theoretical question of the meaning of interrelationships between disciplines, and hence on the acquisition of disciplinary knowledge. To conclude, we will bring attention to the greater complementarity observed between these two approaches in education today, in the context of globalization, universalization (on economic, social, cultural, and political levels), and internationalization of exchanges. Indeed, these two approaches effectively combine the operational modes of interdisciplinary work (the "how") with the aims pursued (the ''why") and the cognitive contents (the ''what").