City centres are the vital social, economic, and cultural nuclei of urban spaces, and, as such, revitalisation of city centres’ economic, social, and environmental aspects can significantly improve citizens’ quality of life. Imam Square, as the most pivotal space in the historic and culturally important city of Hamedan in the west of Iran, is one such centre, playing a key role in all nearby urban functions and activities, and affecting both residents’ social lives and local economic features. The “Urban Catalyst” approach is one of the most realistic approaches to improving urban environmental qualities, and this can be used for regeneration programmes to support new urban development policies that seek to recover multiple types of public domain and which acknowledge the primacy of peripheral areas. The purpose of this paper was thus to investigate the urban catalyst project carried out in Imam Square and to compare the resulting situation with the preceding conditions with particular reference to the area’s former central role as a traffic nucleus. This allowed an assessment of the changes following urban catalytic response, another goal of this research. The methodology was based on mixed, with space syntax used to consider the urban configuration and related quantitative aspects and qualitative analysis, developed based on field observations and interviews. The results demonstrated that after pedestrianisation of the central core and the refurnishing of Imam Square, the degree of integration and connectivity of the square and surrounding areas was significantly improved, which has led to an increase in the quality of public spaces and the number of people present.