Sustainable social entrepreneurship emerges as a multidimensional paradigm at the confluence of social and sustainable entrepreneurship, addressing complex global challenges through integrated value creation across social, environmental, and economic domains. This chapter examines the conceptual foundations, convergences, and divergences of sustainable social entrepreneurship in relation to its parent fields, highlighting its capacity to promote systemic innovation, long-term impact, and intergenerational equity. Social entrepreneurship prioritizes social impact, leveraging hybrid models to address societal issues like poverty and inequality, while sustainable entrepreneurship focuses on environmental preservation and resource efficiency within a triple-bottom-line framework. Sustainable social entrepreneurship synthesizes these objectives, employing innovative, hybrid revenue models to ensure financial autonomy while advancing social and environmental goals. Drawing on a comparative structural analysis, the study delineates distinctions in financial mechanisms, impact scope, business models, and stakeholder engagement across these domains. Key challenges include institutional barriers, such as inadequate legal frameworks, scalability constraints due to context-specific complexities, and financial obstacles stemming from limited investment appeal. Opportunities for synergy arise through multi-stakeholder collaborations involving governments, the private sector, universities, and international organizations, alongside local capacity-building efforts to enhance sustainability. The chapter also forecasts future trends, highlighting the transformative potential of digital technologies, crowdfunding, and Generation Z’s social consciousness in reshaping investment landscapes, necessitating enhanced transparency and real-time impact reporting. Practical recommendations advocate for clear legislative frameworks, tax incentives, and robust digital infrastructure to support sustainable social enterprises alongside entrepreneurial skill development and university-led research to foster innovation. A coherent conceptual framework is proposed to clarify interactions among these entrepreneurship models, guiding policymakers and practitioners in designing effective strategies. By analyzing successful cases and addressing tensions, such as mission drift and cultural resistance, this study highlights the need for tailored impact assessment tools and scalable models to enhance the role of sustainable social entrepreneurship in achieving the United Nations Sustainable Development Goals.