The project set out to examine how governance structures, processes and socio-political systems affect the adoption of new (digital) technologies – e.g. City Digital Twins – that provide evidence for policy making and implementation in urban planning and the management of urban infrastructures. Situating City Digital Twins as next-generation urban models, we analysed the existing practice of using computerised models to support decision-making in the multi-actor governance context of the Cambridge city region in the United Kingdom. The study traced modelling practices and evidence informed decision-making processes across a variety of sectors: transport, energy, land-use planning and telecommunications. Outcomes include the mapping of governance stakeholders in the wider Cambridge area, and the analysis of network relationships, to develop recommendations for the design and implementation of a Cambridge City Digital Twin. The role of citizens in the production of evidence was also examined with a participatory research approach to analysing citizen engagement initiatives and the impact of digital tools on democracy, participation and transparency in the local context. The results of the Cambridge case study are contrasted with international practice and global experiences pertinent to City Digital Twins in British, European and international cities. This comparative perspective provides initial insights to understand generalisation possibilities from the Cambridge case study.