While several authors have focused on the different components of smart city projects and practicalities for their development in large urban areas, despite the absence of a consensual definition of what a smart city is, limited attention has been given to the transformation process achieved by multi-actor relations derived from a sustained network of social innovation and collaboration in smaller cities. Focusing on the Swedish city of Umeå, this study focuses on answering the research question: How is the city of Umeå achieving a smart city transformation? For this purpose, this manuscript inductively examines the opinions and experience of several professionists and decision-makers involved in smart-city projects for a theoretical identification of the observed social phenomena allowing this sustained development. Hence, this work seeks to contribute with further literature development on successful projects to counter an identified problematic of unbalanced development strategies in urbanization projects that generate larger social inequalities as a result of lack of agreement between actors, design failure, policy mismatch and other limitations. This manuscript identifies Umeå’s current development as a best-practice in Sweden of a human-centric smart city project based on a Quadruple-Helix model for social innovation, heavily fostered into practice through citizen trust.