Although the COVID-19 pandemic disrupted the global supply chains, it also provided opportunities that brought the concepts of sustainability and green practices back into the light. Based on the “stakeholders” and “social cognitive” theory, our study intends to empirically explore how fear-uncertainty towards COVID-19 relates positively to both green supply chain management (GSCM) and the firm’s sustainability performance (economic, environmental, and social). In addition, it examines the moderating effect of corporate social responsibility (CSR) (internal CSR and external CSR) on the association between fear-uncertainty towards COVID-19 and GSCM. In this study, we studied a sample of 300 manager-level employees in Egypt. We used partial least squares structural equation modeling (PLS-SEM) to analyze the data and test our hypotheses. Results showed that fear-uncertainty towards COVID-19 positively affect GSCM. Also, external CSR moderates the association among fear-uncertainty towards COVID-19 and GSCM. But it is not moderated by internal CSR. In addition, GSCM positively affects environmental and social performance. However, it has an insignificant effect on economic performance. Besides, GSCM has a significant mediation effect between fear-uncertainty towards COVID-19 and the firm’s environmental and social performance. However, this mediation relationship regarding economic performance is insignificant. Finally, we discussed the theoretical and practical implications at the end of this research.