In recent years, ontological security studies (OSS) have developed an impressive breadth of empirical applications and depth of theoretical advancements. However, despite increasing disciplinary diversity, methodological differences in OSS and the resulting implications have not yet been discussed. Drawing on Jackson’s taxonomy of scientific methodologies, this article outlines that OSS is characterized by considerable methodological diversity cutting across existing distinctions in the field. Greater focus on this diversity is important, as (tacit) underlying methodological assumptions have significant implications concerning the types of knowledge claims that can be advanced. Providing the first systematic discussion of methodological questions in OSS, this article outlines the contours of grounding OSS in neopositivist, critical realist, reflexivist, and analyticist methodologies and provides examples thereof. It then discusses the implications emerging from different methodologies in terms of (1) the production and evaluation of valid knowledge claims about ontological (in)security, (2) the perception of and dealing with ontological and epistemological challenges in the concept of ontological (in)security, and (3) the critical potential of OSS. While highlighting the potential of OSS grounded in analyticism, this article ultimately emphasizes the inherent value of methodological pluralism structured around a common vocabulary enabling meaningful conversations – both within OSS and with International Relations more broadly.