Female leaders continue to face bias in the workplace compared to male leaders. When employees are evaluated differently because of who they are rather than how they perform, an ethical dilemma arises for leaders and organizations. Thus, bridging role congruity and social identity leadership theories, we propose that gender biases in leadership evaluations can be overcome by manipulating diversity at the team level. Across two multiple-source, multiple-wave, and randomized field experiments, we test whether team gender composition restores gender equity in leadership evaluations. In Study 1, we find that male leaders are rated as more prototypical in male-dominated groups, an advantage that is eliminated in gender-balanced groups. In Study 2, we replicate and extend this finding by showing that leader gender and team gender composition interact to predict trust in the leader via perceptions of leader prototypicality. The results show causal support for the social identity model of organizational leadership and a boundary condition of role congruity theory. Beyond moral arguments of fairness, our findings also show how, in the case of gender, team diversity can create a more level playing field for leaders. Finally, we outline the implications of our results for leaders, organizations, business ethics, and society.