This paper explores the role of data norms in the governance of smart cities, with a focus on how these norms shape innovation and collaborative value creation. Data norms are defined as the rules that govern the distribution of data control rights among stakeholders, particularly in relation to civic data sharing, data monetization, and personal data protection. Using the case of Rome’s evolving smart city initiatives, including the Rome Data Platform, RomApp, and the newly launched Julia App, this study examines how these norms are enacted in practice. By analyzing these cases, we highlight the tensions and challenges that emerge when data governance initiatives are deployed in urban settings. The findings offer insights into how data norms influence the development and innovation of smart cities. Future research will expand on these themes through in-depth case studies, investigating the long-term impacts of data governance on the growth of smart cities.