The city of Dezful, with its numerous historical mosques from various periods, represents a valuable example of the continuity and evolution of religious architecture in Iran. Despite damages caused by wars and restoration interventions, many of these mosques have retained their original spatial structure. This study seeks to answer the key question: What are the characteristics of the spatial organization patterns of Dezful’s historical mosques, and how have contextual factors such as the qibla orientation, plot shape, surrounding urban fabric, and the spatial proportions of the prayer halls (shabestans) and courtyards influenced their spatial arrangement? Using a descriptive-analytical method based on both archival research and field studies, this research analyzes the spatial organization of these mosques. Sixteen historical mosques within the urban fabric of Dezful were identified, and among them, six mosques from different historical periods were selected for detailed spatial analysis based on criteria such as historical significance, architectural value, and location. One of the most significant features of Dezful’s mosques is the absence of domes from the early Islamic period through the Qajar era—an element typically reserved for mausoleums—resulting in a distinct reliance on the shabestani (prayer hall-centered) architectural model. In these mosques, the longitudinal axis of the building aligns with the qibla direction, and a clear spatial hierarchy emerges through three primary zones: entrance, courtyard, and shabestan. Courtyards generally exhibit near-square or rectangular proportions, occupying an average of 35% to 40% of the total site area. The spatial organization of Dezful’s mosques is primarily shaped by the qibla orientation, plot configurations, and adjacent structures, with a strong correlation observed between courtyard proportions and the arrangement of prayer halls. Other enduring characteristics include introverted layouts, the consistent use of the tripartite spatial hierarchy centered on the shabestan, and a strong emphasis on the qibla axis. Ultimately, three predominant spatial patterns were identified: North-South,South-West, North, South, and East.