The philosophical literature on punishment concentrates its attention almost exclusively on legal forms of punishment. Indeed, some writers suggest that our common methods for enforcing morality in everyday life (such as angry rebukes, social withdrawal, consumer boycotts, and public shaming) are not really punitive at all. This chapter argues that social punishment is a genuine phenomenon that is deserving of philosophical attention. It distinguishes between formal and informal social punishments and explains how these differ from nonpunitive responses to wrongdoing such as moral criticism and natural penalties.