The main aim of this study was to examine the impact of the Dark Triad (DT) on Organizational Citizenship Behavior (OCB). The mediation effect of Workplace Incivility (WPI) between the relationship of DT and OCB was also analyzed. Furthermore, the moderating role of Islamic Work Ethics (IWE) was also tested between the relationship of WPI and OCB, in terms of the Theory of Threatened Egotism (TTE) and Ethical Climate Theory (ECT). Hypotheses of this study were tested using data of 326 employees (male/female) working in different public sector organizations (Lahore High Court, Lahore, and Rawalpindi Bench, Advocate General, and Attorney General Office). Data was analyzed by using SPSS 25.0 and Smart-PLS, a direct relationship was tested by using hierarchal regression, the indirect effect was tested by using the methods of Barron and Kenny, Sobel, and Hayes, and moderation effect was tested by using PROCESS-macro. Findings support the hypothesis of this study, as workplace incivility indirectly with the presence of dark personality negatively influence the organizational citizenship behavior of employees. Findings further explore that moderation of Islamic work ethics reduces the strength of the negative indirect effect of dark personality via workplace incivility on organizational citizenship behavior. Investigation of this study contribute to the literature of personality psychology and organizational behavior, by showing that the dark side of personality develops the features of uncivil behavior that reduce the level of organizational citizenship behavior, IWE as a potential moderator provide an ethical climate in the organization that reduces the intensity of these negative behaviors.