Sustainability-oriented organizations have typically adopted governance approaches that undertake community participation and collaboration through multistakeholder arrangements. Documented challenges of this model are associated with collaboration and institutional capacity, and include reactive accountability structures, inability to reach consensus, funding limitations, and lack of innovation. Social entrepreneurship is a model used successfully in other social sectors; yet, it has rarely been explored by sustainability-oriented organizations. Nevertheless, research in other sectors has found that social entrepreneurship models of governance can encourage diverse participation from a wide range of social groups. In this paper we consider the value of social entrepreneurship for... sustainability-oriented organizations by examining whether it can help address governance-related challenges associated with collaboration and institutional capacity. Analysis of organizational documents and participant interviews in three biosphere reserves in Atlantic Canada revealed that, over time, these organizations have struggled to maintain their mission objectives, retain productivity, and respond to economic stress. By examining social entrepreneurship theory and its practice in a biosphere reserve in northern Quebec, we learned that social entrepreneurship strategies more effectively target values and expertise, encourage meaningful engagement, foster strategic direction, and promote diversified and stable funding models than the stakeholder models explored. We determined there are opportunities to develop hybrid governance models that offer the benefits of social entrepreneurship while addressing the procedural concerns outlined by the stakeholder model.