Research on social sustainability in developing countries has recently gained importance for both academics and practitioners. Studies in the supply chain management field take either a supplier or a manufacturer perspective that address predominantly corporate social responsibility (CSR) issues referring to the internal stakeholders. Our research integrates the literature on supplier, manufacturer, and customer responsibility and proposes the concept of supply chain social sustainability (SCSS) that refers to addressing social issues within the overall (upstream and downstream) supply chain. Furthermore, we develop and empirically validate scales for measuring SCSS using in-depth interviews and a survey in the Indian manufacturing industry. Our results suggest that SCSS consists of six underlying dimensions, namely equity, safety, health and welfare, philanthropy, ethics, human rights, in a 20-item valid and reliable scale. We discuss the implications of the findings for research and practice and suggest future research avenues.