In U.S. restaurants, racial and ethnic minorities often tip less than whites. These differences in tipping create numerous problems ranging from discriminatory service to restaurant executives’ reluctance to open restaurants in minority communities. Thus, racial differences in tipping need to be sizably reduced, which requires an understanding of their underlying causes. In this paper, we ask a racially and ethnically diverse sample of respondents in an online survey about how much they would tip in a hypothetical dining scenario, how much their best friend would tip, and how much the average person in their area would tip, as well as what the smallest tip a server in their area would consider satisfactory. Analyses of these data indicate that perceived injunctive and descriptive tipping norms independently mediate racial and ethnic differences in tipping. This finding suggests that racial differences in tipping can be reduced with marketing campaigns that promote the dominant 15 to 20 percent injunctive tipping norm and that inform consumers about widespread compliance with that norm.