The search for a more sustainable reality, from the Brundtland Report to the UN Sustainable Development Goals, has gained prominence in the global agenda. Concerning smart cities, unprecedented technological advancement, digital transformations, and accelerated urbanization integrate this agenda. In theory, smart cities encompass sustainability and well-being objectives, but in practice, they remain technocentric and distant from substantial impacts on current challenges. Applying new technologies to outdated solutions without citizens perceivable meaning and usability is insufficient. It is imperative to develop innovative solutions that, through technology, drive genuinely sustainable development and well-being. The literature gap on the absence of models contributing to the widespread adoption and operationalization of the transition to smart cities, coupled with the extensive adoption of Design Thinking, triggered this research. The hypothesis declares that Design Thinking is a suitable collaborative strategy for generating innovative projects for smart cities, meeting well-being needs, and promoting sustainable development. The research aimed to develop a model using the Design Thinking approach for smart city projects, focusing on well-being and sustainable development. The applied methodology encompassed bibliographic, documentary, ex-post-facto, and field research, including an action research phase. The theoretical foundation involved a literature review on smart cities, identifying essential elements, and the Design Thinking stages. The application, motivations, and positive/negative results of Design Thinking operationalization in smart cities were examined through documentary research and ex-post facto analysis of case studies. The information theoretically underpinned the creation of a specific Design Thinking model for Smart City. Field research to test the model occurred in Copacabana, Rio de Janeiro, involving a local population diagnosis with 388 surveys and verification activities for the applicability of two products created for this model—the Map of Local Acting Forces and the Local Innovation Map. Additionally, two stages were added to existing models: Discovery and Distribution, the latter focusing on decentralization and solution multiplication. The research achieved its goal of developing the proposed model, confirming the initial hypothesis, and contributing to operationalizing small local interventions, aligned and integrated to generate impact against current challenges and make cities genuinely smart. Areas for further investigation were identified, including formulating policies balancing technology and well-being and using local identity as a strategy for engagement and action in smart cities.