The growing concern over environmental degradation and resource depletion has led to a shift in supply chain (SC) management towards sustainability, resulting in the emergence of sustainable supply chain (SSC) management (SSCM). In this paper, we investigate the relationship between SC environmental sustainability (SCES), supplier involvement, and corporate financial performance (CFP). Specifically, we explore whether and how SCES influences CFP, and whether supplier involvement mediates this relationship. To achieve this, we conduct a study using bootstrap-based structural-equation modelling to analyze a sample of 110 Taiwanese manufacturing firms, with 1,000 resamples used to enhance the reliability and validity of the results. Our findings indicate that SCES has a significant positive impact on CFP, highlighting the importance of environmental sustainability for firms seeking to achieve superior financial performance. Furthermore, we find that SCES positively influences supplier involvement, which in turn affects CFP. This suggests that supplier involvement is an important mechanism through which SCES contributes to CFP. Our analysis also reveals that supplier involvement mediates the relationship between SCES and CFP, providing empirical evidence that supplier involvement plays a key role in translating sustainability initiatives into financial performance. Overall, our study provides important insights into the benefits of SSCM and highlights the importance of supplier involvement in achieving sustainable and financially successful supply chains. The implications of our findings for researchers and practitioners are discussed, and future research directions are identified.