<p>This study presents a numerical investigation into the behavior of square footings supported on clayey soils reinforced with granular columns, with and without geosynthetic encapsulation, using finite element analysis. Three infill materials—stone aggregate, slate, and sand—are considered to evaluate the effect of column composition. Key parameters such as clay cohesion, elastic modulus, column length-to-diameter (L/D) ratio, and infill type are systematically analyzed to assess their influence on the bearing response of the soil–foundation system. The results indicate that increasing clay cohesion, stiffness, and L/D ratio significantly enhances the bearing capacity of the reinforced ground. Among the materials studied, stone aggregate demonstrates the highest performance, followed by slate and sand. Additionally, geosynthetic encapsulation markedly improves load–settlement behavior, thereby increasing the overall efficiency of granular column systems in soft cohesive soils.</p>