This study examines the relationship between ethical leadership and employee green behaviour, with a particular focus on the moderating role of commitment to the Sustainable Development Goals (SDGs). Employing a dynamic panel data approach using System Generalised Method of Moments (GMM) estimations, the analysis draws on data from 405 firms across multiple industries between 2012 and 2019. The findings reveal that while ethical leadership positively influences employee green behaviour, this effect is significantly amplified in firms demonstrating strong SDG commitment. Specifically, organisations with a high alignment to the SDGs exhibit a stronger relationship between ethical leadership and environmentally responsible employee actions. Moreover, SDG commitment independently exerts a strong positive influence on the green behaviour, regardless of the leadership style. This research contributes to the growing body of literature on sustainable business practices by demonstrating that integrating leadership strategies with institutional sustainability frameworks, such as the SDGs, enhances organisational effectiveness. Theoretically, the study is grounded in Social Learning Theory and Organisational Citizenship Behaviour, while practically, it suggests that firms should embed sustainability into their core strategies to fully leverage the benefits of ethical leadership. Limitations and future research directions are discussed, including the need for industry-specific analyses and deeper exploration of individual-level drivers of green behaviour.