In contrast to the traditional library instruction aim of finding and evaluating information, critical library pedagogies aim to teach students to analyze and challenge the power structures that determine what kind of information is deemed valuable. STEM librarians have been slower to take up these approaches than our colleagues with other disciplinary focuses, yet I argue that critical teaching is one of the most important ways that we can support social justice goals in our work. In this paper, I review the existing literature on critical pedagogies in STEM librarianship and suggest ways for us to develop our practice in this area.