ABSTRACT Everyone has multiple intersecting identities and belongs to several groups. In cases of genocide, how do courts deal with intersecting identities? Are they relevant for the identification of the victims? This paper argues that social identity theory may assist in the legal interpretation of the ‘religious group’ of the law of genocide where individuals are targeted for their – perceived or real –membership of a competing religious group. According to the theory, personal (religious) identity is based on membership in significant social categories that lead to ‘us versus them’ dichotomies, favouring the in-group over the out-group. Identity competition plays a central role in the inception and escalation of intergroup conflicts, including those that occur along religious fault lines. Genocide is a type of intergroup conflict but is not usually framed as such by international criminal lawyers. This paper discusses social identity theory, intergroup conflict, religion, and the case law on genocide. In exploring the relevance of social identity theory for the law of genocide, it argues that the current jurisprudential approach of blending group membership criteria, based on the ‘four corners’ approach, is flawed. The cases of Rwanda, the Former Yugoslavia, Cambodia, India, and Myanmar exemplify the relevance of the theory.