The present manuscript is a theoretical revision of the major theories about intergroup relations and emotions, developed over the last decades in the field of social psychology. Following a general chronological order, we first revise the first individualistic approaches to the field of intergroup relations and social conflict. Afterwards, we revise the realistic group conflict theory and relative deprivation theory. Next, we discuss the social identity and the self-categorization theories and highlight some of the most studied dimensions of intergroup relations within this framework. To conclude, we present some of the most influential appraisal theories of emotions and the theory of intergroup emotions. We claim for an integration of several different approaches when studying intergroup relations and, more specifically, the role of different emotions in explaining instances of intergroup conflict.