Sociology usually conceives of emotions as individual, episodic, and categorical phenomena, while at the same time emphasizing their social and cultural construction. In this article, I argue that this view neglects some essential elements of emotions, in particular affects, and how these are vital to our understanding of sociality. Although affect is an established notion in sociology, it has remained conceptually underdeveloped. The article therefore discusses different perspectives on affect from the vibrant field of affect studies that emphasize their relational and bodily character. In a second step, I contrast and reconcile these views with existing theories of affect in sociology and social psychology and consider a number of essential characteristics that can be used to circumscribe affect. Finally, I introduce concepts from relational sociology and concrete examples to specify the relational character of affect and to develop an understanding of affect that is both theoretically and empirically fruitful.