Companies are adopting innovative and environmentally friendly methods and technologies to mitigate the adverse effects of their products and services on the natural environment. Various internal and external factors influence a company’s ability to comply with such sustainability standards. This study specifically examines the connection between a company’s sustainable supply chain operations and a crucial internal factor, namely leadership. It focuses on comparing and contrasting the impacts of transformational and transactional leadership on green supply chain management (GSCM) and the overall sustainable performance of the company. Using a quantitative approach, the author conducted surveys among employees and managers and utilized structural equation modeling to analyze the model. The findings indicate that transformational leadership significantly impacts GSCM practices and sustainable organizational performance (OSP). However, the association between transactional leadership and GSCM is relatively weak. Additionally, it is observed that GSCM positively contributes to OSP. The results emphasize the importance of upper-level management involvement in green initiatives, particularly GSCM, to enhance the company’s environmental performance and ensure its long-term sustainability.