The aim of this thesis is to shed light on the mechanisms involved in the transition of industrial port territories to the circular economy using a project management tool. The circular economy, which makes it possible to close the loop in the life cycle of materials, offers this type of territory the opportunity to redirect its economic development towards a more sustainable model. Although circular economy activities are developing in European industrial port territories, institutional work on the circular economy in this type of territory is currently limited mainly on identifying these activities. This provides little detail on the transition that is taking place in the territory or the role of the stakeholders. To understand the mechanisms behin this transition, we therefore propose to analyse the conditions for implementing these circular economy activities using a project management tool in the form of a dashboard of indicators created specifically for this type of territory. Our analysis is applied to two cases : Dunkirk, as a pioneer of industrial ecology in France, and North Sea Port, because of its special nature, resulting from the merger of the ports of Ghent in Belgium and Zeeland in the Netherlands. These two cases allow us to demonstrate the impact of our management tool on concrete projects. From a theoretical point of view, the thesis therefore contributes to putting the circular economy back on the port scale by mobilising the concept of the innovation ecosystem. On an empirical level, it provides a management and analysis tool for circular economy projects aimed at stakeholders and managers. ; Cette thèse a pour objet d'éclairer les mécanismes de la transition des territoires industrialo-portuaires vers l'économie circulaire à travers un outils de gestion de projet. L'économie circulaire qui permet de fermer la boucle du cycle de vie des matériaux offre l'opportunité à ce type de territoire de réorienter son développement économique vers un modèle plus durable. Bien que des activités ...