Leaders play a critical role in creating the ethics agenda in organizations. Their communications, decisions, and behaviors influence employees to act ethically or unethically to accomplish organizational goals. To be sure, various reviews within the behavioral ethics literature have highlighted the crucial role that ethical leadership plays in gearing organizations and employees ethically. Yet, numerous documented ethical failings in organizations have evidenced the impact of unethical leadership—where leaders’ unethical conduct or influence on employees promotes unethicality within organizations and generates harmful consequences. Therefore, understanding the darker side of leadership is important. The literature that has emerged in the organizational sciences on the study of unethical leadership, however, is fragmented, creating ambiguities and introducing potential confounds on what constitutes unethical leadership. We review this body of work, summarizing findings on the antecedents, explanatory mechanisms, and consequences of unethical leadership. We then provide an evaluation of the unethical leadership conceptualization, taking stock of previous conceptualizations, problems associated with past approaches, and offer considerations for a conceptualization to progress future scholarship. The goal is to engage scholarly conversation on how to evolve the unethical leadership domain without engaging in logical fallacy or post-hoc rationalization. We offer practical implications for managers to address and minimize unethical leadership within their organizations and outline future research directions to advance our understanding of unethical leadership and its nomological network.