This study aims to evaluate geographic information systems (GIS) as a powerful technological tool for the collection, analysis, management, and presentation of spatial data and to examine its impact on spatial planning processes. In this context, literature review and previous similar studies were used as study materials. The originality of the study lies in presenting a broad perspective on the relationship between GIS and spatial planning, aiming to strengthen the knowledge accumulation in this field and drawing attention to the importance of this relationship. Furthermore, the historical development of GIS and the interaction of spatial planning and GIS applications during the development processes of cities were examined. As a result of the examinations, with the further development of GIS, more conscious and rapid decision-making processes will be provided for the development of sustainable and livable cities, and GIS applications will gain more importance for processing spatial data and supporting decision-making processes. In addition, new urban concepts and approaches emerging with technological developments and globalization will further expand the potential use areas and impact of GIS. Therefore, the role and impact of GIS in spatial planning processes will become even more important in the future.