What is the relationship between business and public policy? Daily news headlines about the corrupting influence of business on government, governmental success in collaborating with business to implement policies in new ways, or international trade and investment negotiations, are all reminders, along with countless others, that business and public policy are interwoven in a great variety of complex and often very high-stakes ways. This complex relationship between business and public policy is evolving through time, together with the accumulated understandings of this relationship generated by those who study it, adding further complexity. In this chapter we provide an overview of this evolution, highlighting key continuities and changes, pointing both to insights that have illuminated the relationship between business and public policy, and gaps in our knowledge that remain to be explored.The chapter is organized into three sections. The first section of this chapter sets out key features of the practice and study of business and public policy that have remained continuously relevant throughout the decades since World War II. These key features include characteristics of and variations within the three main types of actors that are relevant to this field of practice and study -government, business and civil society. These key features also include characteristics of the interactions between these key actors.The second section of this chapter focuses on three interrelated processes of change evident as the practice and study of business and public policy has evolved. The first process of change is a generalized shift from more formal hierarchical organization to more fluid networked organization, which has affected all three types of actors. The second process of change is a much more active and direct contesting of business authority by civil society in the making of public policy. The third process of change is globalization, which has shifted the focus of business and public policy away from a more exclusive focus on the nation-state to one that includes cross-border and global locations and issues.The third and concluding section of this chapter highlights the relevance of insights from the field of business and public policy for some urgent and crucial contemporary public problems, pointing to some future research directions for the field.Understanding this process of historical transformation is helpful not just in appreciating the legacy of the near past, but also in anticipating the future, and what questions need to be asked about it. These questions have an urgency that is amplified by the severity of current challenges that the relationship between business and public policy is implicated in and expectations about the activation or altering of this