Nonstate actors such as social enterprises are increasingly influential for addressing pressing social needs in sub-Saharan Africa. Moving responsibility from the state to private entrepreneurs calls for a greater understanding of how single individuals achieve their social mission in a context characterized by acute poverty and where informal institutions, such as trust and collective norms, are strong governance mechanisms. This study recognizes the role of leader passion as a key element for gaining people’s trust in the social enterprise leader and the social mission. Qualitative data were collected on 37 leaders of Nigerian social enterprises in arenas such as health, women’s rights, children’s rights, AIDS/HIV care and education, and sustainable development. Drawing on 100 semistructured interviews, the authors develop an inductive model illustrating how leader passion interrelates with the social enterprise organizing and outcomes.