During the last couple of years, sustainability has become topical in transnational public–private partnership (TPPP) projects primarily because of the enormous impact TPPP projects have on the environment, economic, and well‐being of people. This paper aims to develop a model that could be used to evaluate the sustainability levels of TPPP projects. The proposed model consists of four categories of social responsibility factors; these include economic, environment, social, and people‐oriented factors. Of the four categories, social factors obtained the highest coefficient (i.e., 0.255) in the TPPP sustainability index equation. The substantive model will enable practitioners to quantify the sustainability levels of TPPP projects prior to their implementations. Moreover, the outputs of this study inform private investors of the key areas to focus on to enhance sustainable development through TPPP project implementations.