Workforce diversity and organizational initiatives to leverage its benefits receive increasing attention. Diversity refers to differences between individuals on any attribute, including but not limited to differences in demographic or job-related characteristics or less apparent attributes such as values, attitudes, and personality. Despite diversity’s potential to boost creativity, innovation, and performance, it does not necessarily lead to such beneficial outcomes. Instead, active diversity management is essential to inhibit potential drawbacks associated with the unfavorable social categorization that diversity can instigate. In this chapter, we shed light on the role of leadership in successfully managing diversity. We offer major theoretical perspectives used to explain diversity (management) effects and summarize evidence regarding diversity leadership in the fields of organizational behavior and organizational psychology as a crucial lever for managing diversity within organizations. In so doing, we highlight perspectives and research in Europe and particularly German-speaking countries which have significantly shaped the current understanding of effective diversity management in organizations. As we will show, leaders can directly influence employee behaviors and attitudes regarding diversity. Yet, they can also indirectly support the effectiveness of diversity-management initiatives, such as diversity training.