This article examines two cases of folklorization led by teachers in Peru between 1939 and 1971, and characterized by the participation of the indigenous and mestizo subjects whose local cultures were transformed into folklore. These cases show teachers as active agents of cultural change in Andean schools, who were responding to de-Indianization by promoting a serrano (pertaining to the Sierra) regional identity among their students. In this fashion, teachers were reinventing “local traditions” to produce a new popular identity based on a common regional bond, through which indigenous and mestizo populations could negotiate new waves of cultural interaction with modernity and national society. The first case analyzes the projects of José María Arguedas and Emilio Barrantes to bring local folklore to the school curriculum and to promote an Andean popular culture. The second case explores school folklore competitions organized autonomously by provincial teachers, in which traditional dances were folklorized and turned into a popular spectacle. While framing both folklorization cases within the study of teachers as local intellectuals, the article also highlights the importance of a magisterial culture in Peru that, drawing from the progressive education movement, viewed teachers as agents of sociocultural change and nationalism.