Since the idea of the smart city was first introduced, over two decades ago, there has been an increasing focus on sustainability as a core strategic priority. However, as the relevance, importance and even definition of sustainability is a function of cultural context, planners must take account of local and regional cultural factors in the selection and adaption of digital infrastructures, as well as in the management and encouragement of public acceptance. Achieving this is not a sequential process, but a concurrent one, as these factors are interdependent. This raises the question of what factors affect and mediate the technology, choice, and public acceptance of smart sustainable cities. This paper attempts to address this question by proposing a new model which advances our current, and considerable, understanding of Technology Acceptance Modelling—using an analysis based on Structural Equation Modelling. This new model, called the Culturally Informed Technology Acceptance Model, was validated using data from a survey of residents of a variety of Saudi Arabian cities. The proposed model is designed around important factors that can be influenced by cultural context, such as digital literacy, process improvements, cost savings and privacy, and is a useful tool for understanding the role of culture in the public acceptance of smart sustainable technology. This design focus is for a number of reasons, such as helping development bodies ensure that the technologies used align with the socio-cultural context. It will also help in the management of at-scale technology roll out in a way that is resource-efficient. Although the Culturally Informed Technology Acceptance Model has been developed and validated using data from Saudi Arabia, the authors believe that it could be adapted to meet the needs of countries/cities that are looking to implement smart city strategies matched to their own distinct socio-cultural identity.