The urgency of transitioning to a circular economy is by now widely recognized. Overexploitation of our earth has been convincingly evidenced globally. An optimal legal instrumentation is one of the prerequisites for fostering the transition to a circular economy. This article identifies and critically assesses recent developments of relevant legal tools and provides some ideas of what else could be needed for the pathway to a circular economy. Since the EU may be seen as a frontrunner in this area and is rapidly developing additional legal instruments to contribute to the transition, the EU is taken as a showcase. Besides EU law, the role of international law is discussed, as well as the question what individual states can do, within the boundaries of internal markets such as the EU. In short, there still is some room for improvement of EU law, especially concerning the establishment of concrete quantifiable general targets and the introduction of general legal principles of sustainable product design. On a global level, there is an urgent need to discuss and develop a legal framework for fostering the transition to a more circular economy.