Current understandings of global environmental governance owe much to the numerous theoretical, empirical, and methodological contributions of Oran Young. Over the course of 50 years, Young has created many of the theories and typologies we use to explain why international environmental institutions form and what types of effects they have and the conditions under which they have them. His contributions have been central to the development of the concepts of institutional dynamics, interplay, and scale. He has made major contributions to environmental policy globally and in the Arctic, both through his own work and by fostering the work of other scholars. This article summarizes the contributions Young has made to the field and introduces the articles in this special issue that honor those contributions.