Urban spaces are increasingly confronted with sustainability, resilience, and social equity challenges. Traditional urban development models, particularly those centered around tourism, often lead to environmental degradation, social inequalities, and economic over-reliance on a single industry. This can create fragile economies and overburdened urban infrastructures. In response to these issues, this research advocates a shift from tourism-driven growth towards a more comprehensive and sustainable urban development model. By incorporating smart city technologies, green infrastructure, and social inclusivity, cities can enhance their resilience while improving the quality of life for residents. The research draws on case studies from cities such as Barcelona, Copenhagen, and Singapore, which have successfully implemented strategies that balance environmental sustainability, economic diversification, and social equity. These cities have integrated smart systems for energy efficiency, promoted green urban spaces to combat pollution, and fostered inclusivity to address social disparities. This research suggests that a holistic approach to urban planning—focused on minimizing environmental impacts, optimizing resource use, and promoting social justice—provides the most effective pathway to sustainable city development. In doing so, urban areas can become more adaptive, livable, and economically robust, offering models that other cities can emulate.