Climate change is a major challenge facing society. Given its intricate links with business, governance scholars have shown an increasing interest in understanding how corporate governance (CG) actors can improve corporate environmental sustainability (CES). In this article, we review the literature focusing on CG and CES. We assess the importance of the motivations, expertise, and power of CG actors at different levels (individual, team, firm, and supra‐firm) for CES. Using this as a guiding framework, we build a multilevel synthesis highlighting the theoretical mechanisms around motivations, expertise, and power suggested in the literature. Based on this synthesis, we present critical reflections on the extant knowledge. Finally, we develop a future research agenda that calls for research at single levels, but also for integrative research examining how CG actors at multiple levels collectively shape CES.