The development of sustainable smart cities (SSCs) is pivotal for contemporary urban expansion, as highlighted by numerous international frameworks and scholarly studies. This study focused on Saudi Arabia to identify and assess the key challenges impeding the evolution of intelligent and sustainable urban environments. By categorizing and hierarchically analyzing these impediments, the research isolates the most significant barriers to SSC advancement. A total of 18 obstacles were identified, organized into four categories, and reviewed using existing scholarly literature. Semi-structured interviews were conducted with stakeholders engaged in executing SSC initiatives, enriching the research from a practical perspective. Additionally, a survey ranked these barriers, revealing that social and economic factors pose the most significant challenges, followed by governance and legal, technology, and environment. The findings of this study offer critical insights for policymakers and governments to mitigate the barriers to SSC development efforts.