The COVID-19 pandemic has resulted in a slew of new business practices that have put the society and environment under strain. This has drawn the attention of supply chain researchers working to address the COVID-19 pandemic's looming social sustainability issues. Prior literature has indicated that collaborative relationships improve organizational performance. Over the past years, problems related to justice are reported (e.g., between Walmart Canada and the Lego group), which might negatively affect the buyer–supplier relationship. In the new normal, the effect of justice on collaborative buyer–supplier relationships on social sustainability in the COVID-19 context is obviously essential but under-explored. The current study examines buyer–supplier collaborative relationships' influence on social sustainability under the moderating effect of justice and big data analytical intelligence. In this paper, we employ the stakeholder resource-based view, loose coupling theory, and resource dependency theory as the theoretical lens to establish the research hypotheses. Using primary survey data collected from supply chain practitioners in South Africa, hypothesis testing is done using a covariance-based structural equation modelling technique. To enhance research rigor, we have checked the dyadic perspectives of both buyers and suppliers. Our empirical results reveal that collaborative buyer–supplier relationships positively influence supplier social sustainability in the new normal era. However, it is relatively stronger from the suppliers’ perspective when compared with the buyers’ perspective. Secondly, the moderating effect of perceptions of organizational justice and big data analytical intelligence on the relationship between collaborative buyer–supplier relationships and supplier social sustainability is also statistically significant. However, it is relatively stronger from the buyers’ perspective when compared with the suppliers’ perspective. These are major findings of this study. Theoretical and managerial implications are further discussed.