<p>Although the relationship between leader narcissism and employee well-being has received increasing scholarly attention, existing findings remain inconsistent and fragmented. To address this gap and synthesize inconsistent findings across diverse studies, this study conducted a meta-analysis of 86 effect sizes from 68 studies. The results showed that leader narcissism was negatively related to both employee psychological and social well-being. Several moderators were identified. Leader age moderated the relationship between leader narcissism and employee social well-being, such that the negative correlation became stronger as leader age increased. Leader gender also moderated this relationship, with a higher proportion of female leaders being associated with a stronger negative correlation. Furthermore, individualism-collectivism moderated the relationship between leader narcissism and employee psychological well-being, with stronger negative effects observed in collectivistic cultures. Finally, the measurement method showed a significant moderating effect on both relationships. Compared to leader self-assessments, employee evaluations of leader narcissism had a stronger negative correlation with employee psychological and social well-being. These findings advance existing research by clarifying the overall relationship between leader narcissism and employee well-being, going beyond prior meta-analyses that focused primarily on narcissists themselves. It also offers the first comprehensive examination of multiple contextual and methodological moderators. Practically, organizations should be cautious when selecting and promoting narcissistic individuals into leadership roles and consider implementing regular 360-degree feedback systems to detect and mitigate their potential negative impact on employees.</p>