What happens when states’ gender identity is endangered? How may a state actor’s gender identity be conceived of and (de)stabilised in the first place? What are the ontological effects of such disruptions? And how do states respond to ruptures in their gender identities or selves? Despite growing attention to gendered narratives in ontological security studies (OSS), the extant scholarship has engaged with gender issues more within states and societies than between them in making sense of state identity and behaviour in international relations. Building upon the existing literature and the theoretical works of Judith Butler, Luce Irigaray, and Hélène Cixous, this article attempts to contribute towards theorising gender more systematically into OSS by demonstrating how it constitutes collective subjectivities and orders imagined state selves in relation to others. Introducing the concept of ontological dislocation, it adopts a non-essentialist performative view of statehood as well as of gender and investigates how states pursue ontological security through gendering themselves and others and what ensues when critical facets of these gendered selves are distorted and disrupted. To illustrate the theorisation empirically, the research focuses on the gender dynamics of Iran’s revolutionary identity and nuclear behaviour to show how destabilisation of gender identity can cause ontological dislocation and lead to a restless scramble to relocate the self.