<p>This study explores the critical role of boundary objects in the context of people-centred smart cities, a new paradigm in urban development that emphasises citizen participation in planning and decision-making. Boundary objects—artefacts, documents, or concepts that facilitate communication and collaboration across different knowledge domains—are increasingly recognized as essential tools in the complex, multi-stakeholder environment of urban governance. Despite extensive research on boundary objects in organizational contexts, their specific application in smart cities remains underexplored. This study addresses this gap by investigating how BOs, particularly collaborative tools and spaces, contribute to innovation, engagement, and knowledge-sharing in people-centred smart cities. Employing a Systematic Literature Review following the PRISMA protocol, this research synthesizes key insights from scholarly articles to comprehensively understand boundary objects' role in urban governance. This study offers a theoretical framework for leveraging boundary objects to enhance the inclusivity and sustainability of smart cities. It suggests avenues for future research, including empirical validation and exploration of boundary objects in diverse geographic and cultural contexts.</p>