Challenges related to the teaching of gender equality in Irish secondary schools are multifaceted and include: insufficient gender equality training for teachers; tendencies towards conservative and religious ethos schools; lack of space in which to address gender topics and issues (including gender identity, gender stereotyping, gender discrimination) in the curriculum and, especially, growing resistance to gender equality and gender mainstreaming from a variety of stakeholders including schools, teachers, parents and students. This paper stems from a transnational European project – GEMINI – aimed at gender mainstreaming through media literacy and presents findings from a study of 12 Irish secondary school teachers in different secondary school types who detail their interest and engagement with gender equality and gender issues, but identify multiple forms of resistance to the delivery of gender equality education. Teachers express fears about rising misogyny among students and raise concerns about the influence of controversial sexist figures like Andrew Tate, especially among boys in Ireland. Findings contribute to the literature on challenges to gender mainstreaming and media literacy in Ireland.