National and religious identification processes can be seen as the basis of the conflict in Northern Ireland, and over the course of the conflict preferred social and political identities became increasingly oppositional and entrenched. This paper reviews this evidence using population-level studies of self-categorized national and religious identity. In an attempt to explore the bases of these identities, two interrelated qualitative studies examining the constructions of national and religious identification are reported. The findings presented suggest the continuing predominance of national and religious identities that have generally been constructed as opposing. Evidence of complete overlap of the identities is evidenced in conflation of religion and nationality in adolescents’ essays. Theoretical sampling of adults living on the border between Northern Ireland, the republic of Ireland, and those in mixed marriages highlight the strategic use of national and religious identities that may act to support divisions in post-Agreement Northern Ireland.