<p>While academic freedom is proven to spur innovation and inquiry, its association with environmental sustainability outcomes, proxied by greenhouse gas (GHG), remains underexplored. This study investigates the association between academic freedom and environmental sustainability and how this association is conditioned by political stability and regulatory quality across Organisation for Economic Co-operation and Development (OECD) countries from 1990 to 2023. Drawing on neo-institutional theory, we use panel data approaches such as fixed effects (FE) and two-step system Generalised Method of Moments (GMM) estimators to control for unobserved heterogeneity and endogeneity. The results reveal a negative association between academic freedom and environmental sustainability, implying that increased academic freedoms are associated with higher emissions. However, this association differs by context: it becomes positive under lower levels of political stability and is attenuated under higher levels of regulatory quality. These results imply that the association between academic freedom and environmental sustainability is contingent on existing institutional environments. The study contributes to the literature by accentuating the importance of considering governance contexts when examining the environmental effects of academic freedom, and proposes that blending institutional frameworks with academic freedom is indispensable for achieving environmental sustainability outcomes.</p>