The New Urban Agenda, the outcome document of the United Nations Habitat III conference in 2016, was adopted by consensus by all 193 member states of the United Nations. The Habitat III leadership has proclaimed that the document represents a “new paradigm” in urban planning, reversing the “over-determined” model of 20th century Western-dominated planning, and embracing more locally-determined forms of informality. This paper examines the intellectual history of the document, and compares it to its antecedents, thereby evaluating the claim that it represents a new paradigm. The conclusion assesses implications for future planning practice, particularly as we confront an age of rapid urbanization in many parts of the globe.