This article presents a portrait of interdisciplinarity in the Quebec school system. Following a contextual overview of this system, including its sociohistorical evolution and current organization in order to define the problem of interdisciplinarity, a second section, beginning with a clarification of terms related to interdisciplinarity, explores the evolution of the concept over the course of the six curricula that have succeeded one another since the beginning of the 20th century, before describing the place of interdisciplinarity in this system. The third section presents the results of research conducted since 1985 on the discourse of primary school teachers concerning interdisciplinarity and its implementation in the classroom. Teacher conceptions and practices related to interdisciplinarity, as well as the place and function they ascribe to it, are dealt with in the next section. Finally, section four presents the results of a recent study on interdisciplinarity at the secondary school level. In the conclusion, we highlight, among other things, the central place given by teachers to socialization, as well as their limited consideration for teaching disciplinary knowledge. [This chapter was translated by Joachim Lépine.]