A numerical simulation of laboratory model tests was carried out to develop an understanding of the behaviour of geocell-reinforced sand, and soft clay foundation beds under a circular footing. The influence of the geometrical parameters of the geocell (width, b and height, h) on the overall performance of the footing was investigated and the pressure-settlement responses of geocell-reinforced foundation beds were predicted and compared with the unreinforced test results. Simulations were also carried out on conventional-type planar geogrid reinforcement to study the relative performance of both reinforcement forms. The influence of the boundary constrains on the behaviour of the foundations was also studied. In all the cases, good agreement between the results obtained from numerical simulations and laboratory experiments was observed. The results demonstrated that the geocell mattress redistributed the footing pressure over a wider area thereby improving the performance of the footing. The pressure-settlement responses corresponding to geocell-reinforced beds were found to be much stiffer in comparison with the unreinforced case indicating that a substantial reduction in footing settlement can be ascertained. The influence of rigid boundaries on the results of reinforced foundation beds in this study was found to be negligible.