Various studies show that men disproportionately vote for populist radical right (PRR) parties. However, research has been unable to fully explain this gender gap. In an attempt to address this research gap, this article theorizes, quantitatively operationalizes and tests the role of ‘protective masculinity’ in the gender gap in PRR support in a cross-sectional study across 18 European countries. Using mediation analysis, we find that ‘protective masculinity’ partly explains the gender gap in PRR support. However, while more men than women hold ‘protective masculinity’ attitudes, women also do. Moderation analysis shows that these women are equally likely as men to support the PRR based on these attitudes. Bridging previous qualitative research on masculinity and quantitative research on PRR support, this article contributes a partial explanation of the gender gap. Its findings call for research on women’s conservatism and PRR support.