Abstract: Cities face many challenges in optimizing city services and enhancing citizens’ quality of life while ensuring economic growth and resource sustainability. To face these continuous challenges, cities are investing in becoming smarter. Tools to support smart city adoption and help cities achieve their goals are in high demand. Existing smart city assessment models vary in the components that they include, which makes it difficult to compare cities. In addition, the various models focus on shortterm outcomes rather than long-term goals, such as sustainability and resiliency, and on technology rather than social, economic, and environmental impacts. Therefore, to ensure that smart cities are sustainable and resilient, there is a need to develop a comprehensive and holistic model to assess smart city initiatives. This research builds and tests a smart city maturity model for assessing the progress and performance of a city in implementing smart solutions across various functional domains. These domains are divided into focus areas that capture different dimensions of a smart city, such as governance, infrastructure, services, data, and the environment. Each focus area has a set of maturity levels that describe the capabilities and outcomes of the city at different stages of development. The maturity model provides a framework for benchmarking, planning, and improving smart city initiatives.