<p>The significance of the role of virtues in guiding people’s behaviours has been extensively discussed in the ethics literature. In leadership research, however, the concept of virtues has not been systematically examined. In this thesis, I propose two concepts, leader virtues and virtuous leadership, positioning the former as antecedent to the latter. I then identify six cardinal leader virtues (i.e., courage, temperance, justice, prudence, humanity and truthfulness) and develop an 18-item scale to measure them. Furthermore, I propose and empirically test a virtues-based model of leadership. Based on a sample of 230 leader-follower dyads, I found that virtuous leadership associates positively with followers’ perceptions of ethical leadership and leader effectiveness, and with follower ethical behaviours and in-role and extra-role performance as evaluated by leaders. Moreover, virtuous leadership positively predicts leader and follower self-reported happiness and life satisfaction. A discussion of the limitations to this research, applied implications of my findings, and future research directions conclude this thesis.</p> / Doctor of Business Administration (DBA)