City standards are a rapidly growing and highly innovative new area of international standards development. They propose tools, techniques and guidelines for the governance of smart and sustainable cities. In this thesis, I survey the standards literature, develop a methodology for their study, and analyse three city standards, the institutions that support them and the material-discursive apparatuses that allow them to take shape. CPA-I_001 is a diagram for seeing, measuring and managing the city as a system of systems. ISO 37120 defines 100 performance indicators for assessing and benchmarking city services and quality of life. And BSI PAS 181 recommends practices for smart city leadership in the integration and management of government services. My decision to focus on the development, circulation and implementation of these standards prompted the use of semi-structured interviews and document analysis; methods capable of following their specific global movements. Drawing on data thus generated, I argue that city standards act as an effective political technology in three capacities: by propagating ideas, materials and techniques; by steering outcomes towards desirable goals; and by assuring city leaders and decision-makers. The case study analysis is augmented by an exploration of the broader intellectual traditions on which the three standards draw. This allows me to reveal their political assumptions and logics, and intervene upon their role in the production of future cities. My research contributes to: empirical work on standards in cities; research methodologies in human geography, and science and technology studies; and conceptual and theoretical debates within Foucault studies, the new materialism, nonrepresentational theory and urban theory.