In this article, we discuss a case study of a feminist society in a girls’ secondary school in England, highlighting how teenage girls use social media to combat sexism. Considering the recent growth of feminist societies in UK schools, there is still a lack of research documenting how young feminists use social media’s feminist content and connections. Addressing this gap, we draw on interviews and social media analyses to examine how girls navigate feminisms online and in school. Despite their multifaceted use of social media, the girls in our research undervalued digital feminism as valid or valued, in large part because of dismissive teacher and peer responses. We conclude by suggesting that schools need to cultivate social media as a legitimate pedagogical space by developing informed adult support for youth engagement with social justice-oriented online content.