With rapid urbanization, cities worldwide have sought innovative, sustainable solutions such as smart city initiatives to leverage technology and data to better manage this growth and the challenges it brings. Developing smart cities requires multi-stakeholder collaboration, including citizens who, as smart citizens, are aware and capable of using technologies to improve their quality of life and actively and equally contribute to making their cities smarter. This study examines how smart citizens are developed by focusing on the underexplored role of public libraries as community organizations in such efforts. To this end, we use comparative case studies of four U.S. public libraries informed by thirty-seven in-depth interviews with representatives from these libraries, local governments, and external partners. Our findings indicate that by providing inclusive access to advanced technology and training, facilitating civic engagement, and promoting innovation, public libraries can develop citizens who, as smart citizens, have the digital skills, agency, and creativity to actively contribute to smart city development. In doing so, public libraries can bridge digital and social divides and thereby develop smart citizens in a way that furthers inclusive and representative participation of their communities in smart city initiatives.