<p>Paradoxical leader behavior (PLB) has attracted considerable interest in recent years. For decades, research has focused on the effect of PLB on behavioral objects such as subordinates, teams, or organization. Limited research investigated the impact of PLB on the actor itself such as leaders. Using The Hot/Cool Framework and Conservation of Resources theory, we examined the effect of PLB on leaders’ insomnia, as well as the mediating mechanism and boundary conditions. An experience sampling method and a multi-wave-multi-source research design were used. Results indicated that PLB heightened leaders’ cognitive stress and emotional dissonance, consequently resulting in leaders’ insomnia. Specifically, PLB exhibited a U-shaped mediating effect on leaders’ insomnia through cognitive stress, and exhibited a linear mediating effect on leaders’ insomnia through emotional dissonance. These relationships were moderated by team performance. The higher the team performance was, the less likely it was that PLB result in leaders’ cognitive stress.</p>