In recent years, dramatic props and costumes have become the focus of a renewed scholarly interest in the performance aspects of Greek drama. This has entailed, in particular, a shift away from enquiries into the ostensible realia of Greek staging to explorations of their complex constructions, semiotics and agencies in the plays and their cultural contexts more widely. My thesis situates itself within these developments but considers the hitherto underexplored phenomenon of (un)dressing in Greek tragedy and comedy. Often treated as a matter of physical costuming, it is a central contention of my work that (un)dress in theatrical representation functions, first and foremost, as an imaginary site where ideas of social identity, difference and transformation may be mapped and negotiated. Drawing on a broad range of relevant tragic and comic scenes, I argue that both dressing and undressing are persistently evoked in Greek drama as social and interactive performances, allowing characters to (re)position themselves and others in a grid of hierarchical relations, including differences of gender and station at their core. At the same time, the agency of (un)dressing is frequently reversed in the dramatic imagination: it is the performance of (un)dressing that determines a character’s social identity rather than vice versa. By exploring this dual capacity of dramatic (un)dressing, my thesis situates the theatrical concepts of (un)dressing within the plays’ socio-political context in the democratic city of Athens: these concepts highlight the precarious position of the democratic citizen male, caught between traditional ideas of essential being and a pervasive public performativity of self, as well as the different representational strategies used to address this uncertainty in tragedy and comedy respectively.