Over 2015-2016, high school students in Brazil occupied hundreds of schools across the country. Students fought to keep public schools open, funded, and functional, against outsourcing and privatisation, and in solidarity with teachers' trade unions and strikes. The 'primavera secundarista' ('student spring') was the most significant school student movement since the struggles against the military dictatorship (1964-1988). This paper firstly addresses the political dynamics of the "primavera secundarista." Secondly, it discusses the movement's educational practices, which flourished in the months that students occupied their schools. Thirdly, it discusses the forms of community and solidarity that students built with other social actors and how they each learnt from this. In doing so, the paper builds on the work of Aziz Choudry and other scholars of social movement learning to argue that such student movements are prime sites of counter-hegemonic knowledge production and dissemination. Shown through the Brazilian high school occupations, the paper highlights how student movements are unusual in being situated in formal epistemic institutions, and yet are not widely recognised, especially in high schools, as blending formal and informal learning to produce and share knowledge-from-below.