Urban morphology, the study of a city’s physical form, provides critical insights into societal forces and spatial organization. Computational tools and geospatial data have revolutionized this field, enabling quantitative, comparative analysis. This study leverages these advancements to compare two seminal Islamic cities: Cairo, Egypt, and Makkah, Saudi Arabia—representing divergent urban evolution shaped by historical layering versus large-scale pilgrimage. Using the Momepy library for Python, we analyzed OpenStreetMap data, calculating morphological indicators at both building and street network levels. Key metrics included tessellation for urban grain, convexity and Equivalent Rectangular Index (ERI) for shape complexity, elongation for building typology, and Edge Betweenness Centrality (EBC) for street network structure. The results reveal a fundamental morphological divergence. Cairo’s organic, millennial growth has produced a heterogeneous, polycentric fabric with wide variation in tessellation areas, greater shape irregularity, and a distributed street network where traffic flow is balanced across an extensive grid. In contrast, Makkah’s pilgrimage-driven development has yielded a more monocentric, consolidated form, evidenced by larger median building areas, more standardized geometries, and a highly channeled network where movement funnels along hierarchical corridors toward the central Haram area. Despite data limitations, the quantitative evidence consistently demonstrates that distinct historical trajectories and urban functions produce uniquely identifiable spatial signatures. This research underscores the efficacy of computational morphometrics for decoding urban form and provides a replicable analytical framework for understanding how different developmental drivers manifest spatially in complex urban environments.