The incorporation of nanoparticles has been recognized as one of the methods of reinforcement of sandwich panels as an effective substitute for popular materials such as metals. This study has examined the low-velocity impact responses of two groups of nanocomposite sandwich panels at different energy levels. Clay-silica nanoparticles and nanoclay-carbon nanotube (CNT) were integrated as nanofillers into the face sheets of sandwich panels. The sandwich panel with glass fibers/epoxy face sheets and a PVC core was fabricated by the hand layup method. The Contact force-time and contact force-displacement curves were recorded at various energy levels of 15, 30, and 50 J. The simultaneous presence of nanoclay and CNT increased impact resistance by 43.2%, 19.8%, and 10.26% at energy levels of 15, 30, and 50 J, respectively, in comparison with the reference sample without nano-particle whereas the presence of nano-silica with nano-clay at some weight fractions weakened the impact resistance. The analysis of SEM images indicates the proper distribution of nanoparticles and the uniform distribution of CNT leading to the increase in impact properties, which are compatible with the mechanical results.