This study investigates the strategic role of carbon disclosure in shaping firm performance and board heterogeneity among heavily polluting companies in Bangladesh from 2013 to 2023. Using empirical data from 150 companies listed on the Dhaka Stock Exchange, the research examines the impact of board diversity—specifically gender, tenure, and educational heterogeneity—on carbon disclosure practices. The findings reveal that board gender and tenure heterogeneity negatively affect carbon disclosure, whereas educational heterogeneity has a positive impact. Additionally, firm performance shows a negative effect on carbon disclosure but does not significantly moderate the influence of board heterogeneity. These results underscore the importance of board diversity in enhancing carbon disclosure practices, thereby contributing to improved environmental management and firm performance in heavily polluting industries in Bangladesh. This research, grounded in legitimacy theory, stakeholder theory, and corporate governance literature, provides valuable insights for academics, practitioners, and policymakers focused on business strategies for environmental sustainability.