This study examines whether top management team (TMT) personality and leadership are associated with organizational effectiveness beyond the effects of CEO personality and leadership, as suggested by upper echelons theory. Using direct measures of personality and leadership, rather than proxy variables from archival sources or demographic data, we found that mean levels of conscientiousness among TMT members were related to lagged indicators of organizational performance, as were CEO conscientiousness and transformational leadership. Follower commitment to the organization was found to be associated with higher levels of transformational leadership from both the CEO and TMT. The results are consistent with the upper echelons perspective that organizational effectiveness is influenced not only by the CEO but also by a dominant coalition of leaders. Yet, the results also show that the CEO plays a distinct role in influencing organizational financial performance and collective organizational commitment. Theoretical and practical implications of these results are discussed.