In light of recent developments such as the COP21 Paris climate agreement, the UN adoption of the Sustainable Development Goals for 2030, and the Habitat III Conference, there is increasing recognition of the role of human settlements as key components of both global challenges and global solutions. “Urban sustainability” under various names has matured over the last three decades not only in planning and related fields, but also in wider professional and popular discourse. In this paper we trace a historical overview of urban sustainability theory and practice, and explain why urban sustainability planning and development currently face limited and inconsistent application. We show that this lack of public uptake is due in part to monitori...