This article sets out to explore the implications of postcolonialism for Irish identity politics, through Tom Murphy’s A Whistle in the Dark. Through the characters of this play, who struggle to define a coherent national identity for themselves in the industrial city of Coventry, Murphy depicts the reality of modern Ireland by locating the play in the pathology of the alienated individual who contradicts the hegemony of Catholic bourgeois nationalist Ireland. By contextualising the liminal aspects of A Whistle in the Dark, the primary aim of the article is to focus on these contradictions and the resulting indeterminate identity that lies at the borderlines of Irish culture. This analysis is informed by Homi Bhabha’s concepts of hybridity and mimicry in relation to the dynamics of colonialism. Through the sense of failure that permeates the play, and the desire to escape the confinements of constructed identity categories, which restrict and trap the characters within ascribed identities, A Whistle in the Dark explores the boundaries between essentialising narratives of Irish identity, and a non-dialectical space. The nature of identity is further complicated by Bhabha’s hybrid voices and performances that allow for an indeterminate plurality of identities to exist in these liminal spaces where they are forced to make their own private myths fuse with the contemporary public identity they must inhabit.