Cities, crucial cultural hubs, mould individual and group identities. The global urban expansion, with over half the population in urban areas, presents interconnected challenges such as pollution, poverty, inequality, ageing infrastructure, resource overconsumption, land use changes, biodiversity impact and climate change. Addressing these demands ambitious actions targeting political, social and economic systems for transformative change. The theoretical framework guiding city transformation centres on an interdisciplinary approach influenced by the Smart and Green Transition. The ‘15-minute city’ concept, emphasizing human scale and urban experience, proposes that cities enable residents to meet daily needs within a short walk or bike ride. The aim of this study was the exploration of its implementation in Greek cities, particularly Thessaloniki, which reveals inherent characteristics supporting the 15-minute concept. Through an interdisciplinary approach rooted in the Smart and Green Transition framework, the research provides concrete guidance for policymakers in tailoring urban planning strategies, allocating resources effectively and crafting policies conducive to successful and sustainable urban transformations. Moreover, prioritizing public engagement highlights the significance of community involvement in shaping urban development plans, ensuring that proposed initiatives align with residents’ needs and desires. In essence, this research contributes tangible insights and actionable recommendations for Greek cities, paving the way for more liveable, resilient and sustainable urban environments.