Social entrepreneurs play a pivotal role in shaping entrepreneurial ecosystems, particularly in contexts marked by institutional voids or social inequality. This study examines how social entrepreneurs contribute to the formation and sustainability of entrepreneurial ecosystems, as well as the implications of their withdrawal. Drawing from ecosystem theory and institutional entrepreneurship, the research investigates key mechanisms—such as resource mobilization, stakeholder collaboration, and normative influence—that enable social entrepreneurs to initiate systemic change. Using multiple case studies across emerging markets, the study reveals that social entrepreneurs not only create value through innovation but also embed structures that support long-term community empowerment. However, their withdrawal—due to burnout, funding limitations, or strategic pivoting—can lead to significant destabilization unless succession or institutional embedding occurs. The findings offer practical insights for policy-makers, impact investors, and ecosystem designers seeking to leverage and sustain the catalytic role of social entrepreneurship.