This chapter explores how environmental historians might interact with, and have interacted with, policymaking and the broader suite of environmental governance that operates at many jurisdictional scales. It offers frameworks, concepts, and examples for the historian’s toolbox. It explores the nature of “policy” and encourages historians to appreciate the significant and complex policy studies literature. It touches upon the larger tradition of “historians and policy”, especially as practiced in the United States and Britain. The chapter then focuses on a range of specific areas and challenges in which historians have demonstrated skill and effectiveness in contributing to environmental policymaking, including around access to environmental data and information, in cultivating and encouraging policy deliberation and community engagement, and in participating in interdisciplinary “communities of practice” for environmental policymaking and ongoing practice. The weight of experience and evidence from historians and other scholars participating in policymaking suggests that contributing to policymaking and governance is difficult and time consuming, and that sustained work must be combined with patience and tenacity to achieve even small improvements and changes.