This article proceeds from a critical analysis of gendered narratives of nationhood as manifested in far-right populist politics and discourses in response to major security challenges. We focus on how such narratives exemplify gendered nationalism and inform the discourses of populist political leaders and their followers, with a particular focus on the USA and the UK. We proceed from an engagement with the ontological security literature to show how masculine imaginations and fantasies of fear, hate and anger—‘toxic masculinity’—are in fact gendered responses to ontological insecurity across two major cases of insecurity: climate change and the global coronavirus pandemic. The global coronavirus pandemic and climate denialism have gendered dimensions in populist, masculine discourses, as exemplified in the response to the climate activist Greta Thunberg and to the rejection of experts and lockdown measures in the case of Covid-19. A key contention is that the reinvention of ‘nationhood’, along gendered lines, has created a foundation for governing practices in which hegemonic discourses turn into normalizing narratives that justify masculinist responses to ontological insecurity.