ABSTRACT In this article we develop a ‘hauntological’ reading of republicanism in postcolonial Ireland. This reading takes as its object the ways in which the politics of remembering – and remembering republican politics in particular – is equally a politics of time. Exploring the politics of republicanism through the lens of entangled temporalities, we develop an understanding of a particular mode of political desire. This republican political desire holds open the demand for a radical interrogation of the (post)colonial given. As such, it takes the form of a ‘dangerous memory’. Through the concept of a ‘dangerous memory’, we excavate a certain republican politics of refusal, that haunts the legitimacy and automatic reproduction of the postcolonial settlement and the attendant proprietary relations of inequality that it formalizes – culturally, politically, economically and legally. This theoretical interpretation of Irish republican hauntology is empirically explored through three historical layers and entangled temporalities that are organized around the ghosts of Roger Casement, a radical republican figure. The dangerous memories of Casement not only disrupt the canonical or official interpretation of Irish republicanism, but also open up the left-republican possibility to further interrogate the postcolonial present, both in Ireland and beyond.