In recent years, private regulations—instances where non-state actors set rules to govern behavior—have emerged as a vibrant source of global environmental governance. With a particular focus on forest, fisheries and agricultural certification programs, this chapter discusses demand and supply factors contributing to the emergence of private regulatory programs, the evolution of these initiatives, and consequences for problem amelioration. Taking the insights from these lead sectors, we review the private regulatory activities on climate change, drawing parallels and noting differences that emerge.