The development of sustainable smart city (SC) services is often carried out with limited resources, but there is little discussion about the strategic priority of promoting SC development from the citizens’ perspective. This study developed a decision-making approach to determine the supply and demand priority of SC services using utility and need theories, with Hong Kong as a case study. The results show that smart environment services should be prioritized for all population groups, while the differences in priority among older adults, people with lower digital literacy, and people with lower income were relatively small. On the one hand, the supply of SC services should be prioritized for those that are closely linked to citizens’ daily lives, have a long-term impact on communities, and are targeted to large user groups. On the other hand, priority should be given to those services that meet citizens’ demands for physiological, safety, and self-actualization needs. This study enriches the theoretical framework of people-centric SC research through the innovative integration of Bradley-Terry and rank-ordered logit models for determining the development priority for SC services, which can serve as a practical decision-making tool for policy makers to effectively allocate resources for sustainable SC development.