Land utilization without considering suitability can lead to capital loss and environmental degradation. Effective land use planning is crucial for managing environmental resources. The present study in three counties of Fars Province in southern Iran confidently assessed the ecological capability for industrial, rural, and urban development. This study employed a rigorous methodology to examine six general criteria (physiography, soil, geology, vegetation, water, and climate) and 16 indicators linked to these criteria. The Iranian ecological model served as the foundation for this analysis. A Geographic Information System (GIS) was used to overlay ecological indicator layers and determine the final suitability map. Consequently, following the Law of Maximum Limitation and Boilen's logic between the indicators, the final suitability map was determined. The resulting map classified areas into nearly suitable and unsuitable. Furthermore, the study evaluated the current industrial, rural, and urban land uses by overlaying these layers on the ecological capability map. The findings revealed that a widespread area of urban, industrial, and especially rural areas is classified as unsuitable, highlighting the disregard for environmental capacity in land development. These critical findings emphasize the necessity of conscientious land use planning to mitigate environmental challenges stemming from rapid development.