Climate change and rapid urbanization have amplified environmental and social vulnerabilities in semi-arid regions, making resilience-oriented approaches to urban design increasingly urgent. Dezful, a historic city in southwestern Iran, represents a unique context where centuries-old cultural traditions coexist with severe climatic pressures. The city experiences prolonged hot seasons, irregular rainfall patterns, and frequent flash floods, while also facing growing demands on its limited water resources. These conditions present both challenges and opportunities for the integration of Nature-Based Urban Design (NBUD) strategies into its planning and development processes. Dezful’s natural assets—including extensive gardens, productive agricultural lands, and the riparian habitats of the Dez River—constitute a valuable ecological foundation for embedding ecosystem services into urban spaces. Complementing these environmental features are locally adapted architectural elements such as Shavadan (underground chambers designed for thermal comfort), Qomesh (ventilation and water-access shafts), and Kat (stone structures engineered for microclimate regulation). Together, these systems embody a long-standing synergy between human ingenuity and the natural environment, offering inspiration for contemporary climate-adaptive urban design. The proposed NBUD framework for Dezful emphasizes the restoration and enhancement of green–blue infrastructures, including riparian buffers and interconnected ecological corridors, to mitigate flood hazards and reduce the urban heat island effect. Strategies also include the revitalization of historic gardens into multifunctional public spaces that simultaneously preserve cultural heritage and provide recreational, ecological, and social benefits. Integrating urban agriculture within vacant or underutilized spaces is identified as a pathway to enhance food security while strengthening community engagement with the land. Methodologically, the chapter combines spatial analysis, participatory design workshops, and climate-responsive design principles to develop an adaptable planning model. Quantitative assessments—such as thermal mapping and flood modeling—are paired with qualitative insights from local stakeholders to ensure cultural and ecological relevance. This approach underscores the necessity of integrating traditional knowledge systems with modern sustainability practices. The findings suggest that implementing the Nature-Based Urban Development (NBUD) framework in Dezful can yield multiple co-benefits, from mitigating climate risks such as flooding and heat stress to fostering social cohesion through equitable, nature-rich public spaces. The innovative contribution of this chapter lies in integrating green–blue infrastructure planning with climate-responsive urban design specifically tailored to semi-arid cities. By developing a context-sensitive NBUD framework that connects riparian restoration, ecological corridors, and public space networks, the study demonstrates how nature-based strategies can function as essential urban infrastructure rather than ornamental elements. This approach not only reframes urban planning toward resilience and sustainability but also provides a transferable framework for other semi-arid cities facing similar climatic, ecological, and socio-cultural conditions. In doing so, the chapter contributes to advancing global sustainable urban development agendas, particularly SDG 11, SDG 13, and SDG 15.