Social entrepreneurship (SE) is a new form of entrepreneurship dedicated to the creation of social value for its beneficiaries, either as a for-profit or not-for-profit enterprise. While, over the years, research has yielded notable insights regarding, e.g., social entrepreneurial nascence and motivations or contextual factors (dis-)favoring SE activity, not much is known about the resources social entrepreneurs have to maintain their mental well-being (MWB), which is essential for successfully accomplishing their social missions. The current study takes a psychological view, identifies four resource clusters (personality, work design, external support, and provision of social impact), and integrates these to empirically explore their predictive values for job-specific and general MWB. Building on a representative sample of South African social entrepreneurs from Gauteng and Limpopo Provinces, we apply structural equation modeling and find positive effects on social entrepreneur’s MWB in all resource clusters. Moreover, comparing for-profit and not-for profit social entrepreneurs yields differences in the levels and mechanisms of their MWB resources. Despite notable limitations, such as using cross-sectional data and a limited sample generalizability, our work offers the first framework shedding light on social entrepreneurs’ MWB-resources that can serve as a basis for future research and help SE-support programs to sustainably promote social entrepreneurs’ MWB.