This chapter investigated the contrasting trajectories of smart city development in developed and developing economies, situating these within the broader context of rapid global urbanisation. It highlighted that while smart city initiatives often prioritise sustainability, governance, and quality of life, their success hinges on economic capacity, infrastructure, and coherent policy frameworks. Case studies from cities such as Singapore, London, and Amsterdam also exemplified advanced data-driven models but revealed concerns over digital divides and privacy issues. Conversely, in developing regions such as Africa, South Asia, and Latin America, the chapter showed that implementation is hampered by inadequate infrastructure, reliance on external funding, and political instability. Innovative, low-cost solutions exist but often fall short of addressing deeper structural governance issues. Moreover, the chapter critiqued the uncritical transfer of smart city models from the Global North to the Global South, arguing for locally tailored approaches. It also examined emerging technologies, including AI, IoT, and blockchain, as well as their ethical implications. Consequently, the chapter concludes by advocating for inclusive, adaptive, and ethically governed smart city frameworks that prioritise human development over purely technological advancement.