This article theorizes the global anti-gender movement in education. This conservative movement opposes "gender ideology," which is perceived as a threat to traditional social values. Building on a systematic literature review of how the anti-gender movement shapes educational policies, politics, and practices, with a specific focus on Brazil and the US, this article presents a theoretical framework for conceptualizing: 1) the contested meanings of "gender ideology"; 2) its discursive components; 3) the characteristics and composition of anti-gender alliances; 4) the anti-gender agenda's manifestations in curriculum, pedagogy, the social relations of schooling, and education policy. We attempt to highlight the ways in which anti-gender politics often operate together with racial politics to reveal the ways in which conservative, right-wing alliances, frequently predicated on and united through anti-Blackness, white supremacy, homophobia, transphobia, and misogyny, exert influence on educational policies, politics, and practices to simultaneously maintain a white supremacist, cis-heteronormative, and patriarchal state. We conclude with a discussion of the contradictions of this agenda and resistances to these conservative attacks on equity, inclusion, diversity, and human rights.