In this introduction to special issue, we elaborate our use of the concept affective body politics in the context of social media. Bringing together two theoretical concepts, the notion of “body politics” and that of “affective politics,” we direct attention to the carnal ways in which bodies experience practices of governance, how they affect and are affected by other bodies. The introduction maps out some of the interdisciplinary voices that study affect online, provides an overview of the papers in this special issue, and concludes by considering ideas for further discussion.