Recent behavioral economics studies have shown that third parties compensate players in Dictator, Ultimatum, and Trust games. However, there are almost no studies about what drives third parties to compensate victims in such games. It can be argued that compensation is a form of helping; and helping behavior, in a variety of forms, has been widely researched, especially with regard to motivators. Previous work on helping behavior has focused on empathic concern as a primary driver. In sharp contrast, anger is often seen as an antisocial motivator resulting in aggression. However, other research has shown that moral outrage, anger evoked by the violation of a moral rule or a social norm, can lead to the punishment of a perpetrator, often described as altruistic or pro-social punishment. Some of the motivations for pro-social punishment, namely a concern for justice or the restoration of community values, can also be realized through victim compensation. We therefore propose the hypothesis that moral outrage leads to compensating behavior above and beyond what is predicted by empathic concern, but only when a social norm has been violated. We test this hypothesis in two studies, both of which use modified trust games in which the investor experiences a loss due either to a social norm violation or some other cause. Study 1 shows that trait moral outrage predicts third-party compensatory behavior above and beyond empathic concern, but only when a social norm is violated. To better understand the causal mechanism, Study 2 directly manipulated moral outrage, showing again that moral outrage leads to compensation, but only when a social norm is violated.