International trusteeship of post‐conflict territories by multilateral institutions or foreign states received renewed attention in the wake of its application in Kosovo and East Timor during the 1990s. Subsequently, interventions in Afghanistan and Iraq have contributed to the intensity of critical discussion over post‐Westphalian sovereignty approaches and competing norms regarding human rights, nationalism, and security. This article seeks to establish normative and practical criteria for the application of the trusteeship model to weak, fragile, or post‐conflict societies. In particular, I propose that consent of the local population, multilateral international approval and participation, and absence of local institutional capacity for effective governance form the key dimensions of the legitimacy and feasibility of a potential international trusteeship. Building on the literatures on quasi‐states, state building, liberal institutionalism, and critiques of international intervention, the article tests the utility of these criteria through illustrations of international trusteeships in East Timor, Kosovo, and through a more extensive analysis of the Palestinian territories. It concludes that, despite frustrations over the Israel‐Palestinian peace process in the absence of intensive external intervention, the Palestinian territories do not meet the proposed criteria for the effective and legitimate application of an international trusteeship.