The 21st century Middle East has witnessed an unprecedented rise in the political relevance of sectarian identities (particularly Sunni and Shi’a Muslim identities). As a result, recent commentary on the region has often been distorted by an inflated focus on an ill-defined ‘sectarianism’. This has reified a number of misplaced assumptions regarding the Middle Eastern nation-state and particularly regarding the relation between sectarian identity/‘sectarianism’ and national identity/nationalism. The two are presumed to be mutually exclusive: hence a normatively ‘good’, ‘modern’, secularized and territorialized national identity is juxtaposed against a normatively ‘bad’, ‘pre-modern’, religious and transnational sectarian identity. This false dichotomization is a reflection of unfounded assumptions regarding the content of nationalism combined with problematic reductions of sectarian identity to its religious/doctrinal component. Contrary to conventional wisdom, modern sectarian identities are deeply embedded in the prism of the nation-state and are inextricably linked to nationalism and national identity. This chapter seeks to provide a corrective to the debate on nationalism and ‘sectarianism’ in the Middle East. It begins by interrogating the concepts of ‘sectarianism’ and sectarian identity before moving on to the inter-relation between sectarian identity and nationalism in the modern Middle East. The chapter’s main case study is modern Iraq but, as will be seen, the Iraqi example is significantly echoed in the cases of Bahrain, Syria and Lebanon. Following the example of Brubaker, Friedland and others, it will be argued that, rather than polarity, sectarian and national identities are characterised by an inescapable and mutually informing intertwinement.