With the expansion of industrial activities and the growing expectations of local communities regarding the social role of business enterprises, corporate social responsibility (CSR) has become one of the most important mechanisms for promoting social sustainability and strengthening industry–community relationships. Nevertheless, developing effective CSR policies and aligning them with the needs and priorities of host communities remains a significant challenge. The present study aimed to develop a CSR policy model for Gohar Zamin Steel Company to promote social sustainability in Bardsir. An exploratory mixed-methods design was employed, drawing on the Walt and Gilson policy analysis framework. Qualitative data were collected through semi-structured interviews with experts in industry, management, policymaking, and local development and were analyzed using thematic analysis. In the quantitative phase, the perspectives of citizens and experts regarding CSR priorities were examined. The findings revealed that effective CSR policymaking requires simultaneous attention to four key dimensions: context, actors, process, and policy content. Furthermore, stakeholder participation, transparency, social trust-building, local needs assessment, and continuous evaluation emerged as essential requirements of the policymaking process. Based on the findings, a CSR policy model was developed that can, on the one hand, contribute to strengthening social capital, improving quality of life, and promoting social sustainability in industrial host communities and, on the other hand, enrich the literature on CSR policymaking and social sustainability, particularly in developing countries.