This chapter discusses different conceptualisations of myth in peacebuilding and intervention research. It argues that myth concepts are useful to explore the powerful foundational narratives and commonly held beliefs underpinning international politics. Myths have the effect of imposing and maintaining an already dominant social order in the international system, but they also allow narratives of change to develop. Our discussion is organised into four sections and distinguishes studies which understand myths as calculated strategy or social construction, and analyses that focus on the performative effects of myths, namely their role as ideological delusion or as necessary fiction. The chapter ends with a brief discussion of the future of this strand of research in times of declining interest in liberal state- and peacebuilding interventions.