The relationship between self-monitoring and leadership has been debated. We attempt to resolve this debate through a meta-analysis (N = 9,029 across 55 samples). Since this is the first meta-analysis that focuses on this relationship, we were able to study both focal constructs at a granular level. As hypothesized, self-monitoring is positively associated with leadership emergence and leadership effectiveness. Whereas self-monitoring is positively related to managerial leadership, its relationship with transactional leadership is non-significant. Contrary to our prediction that self-monitoring is negatively related to authentic leadership and to transformational leadership, we found positive relationships. Importantly, the relationship between self-monitoring and leadership variables is typically non-significant when the latter is measured by subordinate ratings. This casts doubt on the general finding that self-monitoring is positively related to leadership. Also, the relationships significantly differ when self-monitoring was measured by different scales. Implications for theory and practice are discussed.