A growing body of leadership literature focuses on leader and follower identity dynamics, levels, processes of development and outcomes. Despite the importance of the phenomena, there has been surprisingly little effort to systematically review the widely dispersed literature on leader and follower identity. In this review we map existing studies on a multilevel framework that integrates levels-of-the self (individual, relational and collective) with the levels-of-analysis (intrapersonal, interpersonal and group) on which leader or follower identity work takes place. We also synthesize work from multiple research paradigms, such as social psychology experimental studies, narrative accounts of leaders' identity work and field studies on antecedents, outcomes, mediating mechanisms and boundary conditions. Finally, we outline implications for leadership development and call attention to key themes we see ripe for future research.