Urban tourism in Hamedan faces increasing fragility due to the triple interaction of escalating climatic hazards, unsustainable development patterns, and structural-institutional governance weaknesses. This study aimed to develop a paradigm model of climate resilience in sustainable urban tourism development in Hamedan. Using the systematic Grounded Theory methodology of Strauss and Corbin, data were collected through 35 in-depth semi-structured interviews with key stakeholders including government officials, cultural heritage and environmental experts, academics, private sector representatives, and local community members, using purposive theoretical sampling continued until theoretical saturation. Data analysis was performed in three stages—open coding (extracting 174 initial codes), axial coding (organizing into 8 categories), and selective coding—using MAXQDA 2020. Findings yielded a six-component paradigm model: causal conditions (climatic hazards, unsustainable pressures, institutional weaknesses), core phenomenon (the process of realizing sustainable tourism development through integrated climate resilience strategies), context (natural-ecological, cultural-historical, socio-economic), intervening conditions (barriers and facilitators), five strategy categories (adaptive-risk reduction, protective-restorative, institutional-governance, empowerment-participatory, knowledge-technological), and consequences (positive and negative feedback loops). Quantitative TOPSIS analysis revealed that knowledge-technological strategies have the highest short-term priority (CLi = 1.000), while institutional-governance and empowerment-participatory strategies are identified as fundamental prerequisites for long-term transformation. The principal recommendation centers on establishing a cross-sectoral coordinating body (High Council for Tourism Resilience) and empowering local communities for participatory attraction management. The proposed paradigm model serves as a diagnostic-analytical tool for policymakers in Hamedan and similar historical-natural tourism destinations in Iran.