The bazaar in Iran's historic cities is not merely a commercial space or a historical relic, but a fundamental element structuring the form and function of the city. Yet most theories and studies in urban morphology remain grounded in Western urban patterns, giving limited attention to the bazaar as a multi-scalar, structuring element. Accordingly, this study aims to redefine the bazaar within urban morphology studies and to assess its role in structuring the form and function of the city. A sequential exploratory mixed-methods approach was employed: in the first stage, a conceptual model was developed through a systematic literature review, qualitative content analysis, and index validation using the Fuzzy Delphi method; the model was then evaluated in the historic fabric of Kerman using spatial network analysis, Geographic Information System (GIS) analysis, and statistical methods. The findings show that the historic bazaar of Kerman simultaneously plays a structuring role at three scales: at the macro scale, it remains the backbone of spatial organization and the core of centrality in the historic fabric; at the meso scale, it organizes the relationship between the street network, mass-and-void configuration, and activity distribution; and at the micro scale, neighborhoods connected to the bazaar exhibit the highest integration, centrality, and spatial coherence, while contemporary physical interventions have disrupted this historic network and weakened its role. The study concludes that the historic bazaar of Kerman, as an "organic whole" and a self-organizing structure, has evolved gradually through a micro-to-macro process and remains the key mechanism linking the structure and function of urban form. Accordingly, the bazaar should be redefined beyond a commercial space, as a structuring and fundamental element of urban morphology—an approach that can inform conservation, regeneration, and planning policies for historic cities.