Recent advancements in the area of workplace mistreatment have begun to challenge our view of who is affected by this phenomenon. Whereas it was initially assumed that mistreatment affected a small subset of employees who were directly targeted by negative treatment, empirical work has documented that employees who observe or become aware of others being mistreated are also adversely affected. However, the extant literature examining vicarious mistreatment has developed in silos centered around individual mistreatment constructs and individual outcome domains, and there is currently little integration among these bodies of work. As such, this paper draws on a systematic review of empirical studies examining vicarious mistreatment to summarize its antecedents and outcomes. The review further enumerates the mechanisms that transmit the effects of vicarious mistreatment to third-party outcomes and the moderating variables that may mitigate or amplify the impact of vicarious mistreatment. The culmination of this review is the development of a dual process model of vicarious mistreatment that integrates prior theoretical perspectives into an overarching framework to guide subsequent research. The authors then conclude by providing a road map for future theoretical and empirical work on vicarious mistreatment. Included within the future research agenda is a constructive critique of current research designs and methodological approaches that may undermine the field’s understanding of how vicarious mistreatment operates.