This article aims to address why religion has been marginalised in international relations (IR) and discusses its implications. The first section examines the literature on the secular roots of the discipline of IR and how theoretical inputs from the West are shaped by context-specific European events and philosophies that are not ‘universal’ in nature. The second part delves into how the existing theoretical traditions of IR—realism, liberalism and constructivism—can incorporate religion as a variable in evaluating international politics. The final section will explore the problems with the recent spate of literature from the West after 9/11 on religion and IR. The article contends that the Indian conception of secularism, which has been studied in-depth vis-à-vis Indian domestic politics but not international politics, can be further examined to formulate frameworks that understand and deal with religion in IR.