<p>We investigate how the alignment of trust between leaders and their subordinates could influence leaders’ unethical behavior that specifically benefits their subordinates (i.e., unethical pro-subordinate behavior). Drawing on social identity theory, we propose that when there is a high level of trust alignment between leaders and subordinates, leaders may develop stronger identification with their subordinates, could create a psychological foundation for prioritizing subordinate interests—potentially through unethical means. Based on time-lagged data collected from 285 leader-subordinate dyads in South Korean police riot squads using polynomial regression and response surface analysis, we found that when leaders and subordinates have congruent levels of trust in each other, leaders tend to identify more strongly with their subordinates, which in turn is associated with a higher likelihood of engaging in unethical pro-subordinate behavior. These findings contribute to our understanding of the complex ethical dynamics within leader-subordinate relationships and offer important implications for leadership development.</p>