Glass Fibre-Reinforced Polymer (GFRP) bars have been considered suitable in replacing steel reinforcement in Reinforced Concrete (RC) structures due to their corrosion resistant properties, chemical resistant properties, low cost, and high ultimate strength. Recently, low-velocity impact loads on structures and structural components have been receiving increasing research attention due to the increase in the terrorist attacks worldwide. This paper numerically investigates the behaviour of GFRP-RC beams under impact loads. The numerical model has been validated against the experimental data in terms of failure modes, midspan deflection, strain in reinforcement, and impact forces. The numerical results have been found to be in a very good agreement with the experimental results. Also, an extensive parametric study has been carried out in this paper to investigate the effects of the reinforcement ratio, compressive strength of concrete, and drop hammer properties on midspan deflections, impact forces and reaction forces of the GFRP-RC beams.