Social entrepreneurs design and implement innovative, sustainable, and scalable solutions to pressing social challenges across the world. While the success of their ventures is impacted by numerous factors, their long-term viability and endurance depends on the relationships built with diverse stakeholders. The praxis of grassroots diplomacy facilitates the development of harmonious and effective relationships that catalyze social change. This art and science of pro-active conflict avoidance and resolution helps navigate multifaceted social dynamics and develop successful entrepreneurial alliances and ecosystems. With the help of several examples and mini case-studies, this article articulates the meaning and importance of grassroots diplomacy. A conceptual framework based on six core competencies of proactive scenario planning, empathy, trust-based relationship building, equitable collaboration, conflict resolution, and ethical reflection is presented. Finally, a practical methodology that animates these core competences into a structured process that strengthens partnerships and ventures is presented. These concepts, competencies and methodologies are built upon the central tenets of systems thinking and self-determination that leads to systemic self-determined improvement of lives and livelihoods.