The relationship between constitutional and administrative law is usually seen as a non-problem, as the conventional wisdom is that there is no distinction between them, or that nothing of significance hangs on their relationship. The sense that there is nothing significant about the constitutional-administrative law relationship is reinforced by the blurring of the boundary between them in many jurisdictions that are prominent ‘exporters’ of public law. This paper develops and defends an opposing view: the relationship between administrative law and constitutional law is significant. It offers a foundational insight into the nature of both areas of law. The paper develops the idea that administrative law regulates delegates and constitutional law regulates delegators. This idea helps us make sense of the nature and content of administrative law, as well as how it relates to constitutional law.