Research has demonstrated that ethical leadership helps to limit subordinates’ workplace deviance. In this chapter, we draw on social cognitive theory of moral thought and action to further understand why ethical leadership has a preventing impact on workplace deviance. We propose that the key mechanism between ethical leadership and deviance is moral disengagement, which refers to the process of making unethical behavior morally or socially acceptable. Specifically, subordinates learn cognitively and emotionally from ethical leaders to minimize the adoption of moral disengagement. When they decrease the use of moral disengagement, subordinates are less likely to display deviant behavior.