Customer verbal aggression is a core social stressor among retail workers which impairs wellbeing via emotional dissonance. This study examined two moderators—supervisor support and ethnic minority status—in this well-established relationship. In addition, it tested a moderated moderated mediation model to explore whether the moderation effects of supervisor support on the indirect relationship between customer verbal aggression and wellbeing (measured as positive affect) via emotional dissonance vary between ethnic minority and ethnic majority workers. Retail workers of one retail chain (N = 603) completed our paper-pencil survey at two measurement points. Path modeling showed that emotional dissonance mediates between customer verbal aggression and positive affect. Taken alone, neither supervisor support nor ethnic minority status moderated this relationship. However, their combination had a significant moderating effect; supervisor support moderated the indirect effect of customer verbal aggression on positive affect through emotional dissonance only among ethnic minority workers. Surprisingly, supervisor support amplified this mediation. We discuss our findings by considering the role of supervisor support and the status of ethnic minority workers.