In this paper, the impact resistance of multilayer sandwich composites was investigated. The outer layers of the composites were made of 1 mm thick 7075 aluminum plates, while the interior consisted of para-aramid fabric in a laminate with a thermoplastic polymer matrix. Three panel variants were prepared: one with a single inner layer of para-aramid fabric, one with six layers, and one with eight layers. During ballistic tests, the samples were fired with 9×19 mm Parabellum FMJ and 5.56×45 mm FMJ M193 ammunition with initial velocities of 350 ± 10 m/s for the 9×19 mm projectile and 770 ± 10 m/s for the 5.56×45 mm projectile, in accordance with the CEN EN 1522 standard. A two-step homogenization method was used to evaluate the material behavior, based on the average laminate results from quasi-static tensile tests, which were then supplemented and compared with the fiber-volume-fraction measurements obtained via optical microscopy. Then, numerical simulations were carried out in the ABAQUS/Explicit dynamic analysis environment using a hybrid FEM/SPH approach. An inverse calibration method was used to preserve the material dynamic behavior. The single-layer sample was fully penetrated by the 9×19 mm projectile, whereas the panels containing six and eight layers were not fully penetrated by the 9×19 mm projectile, but were completely perforated by the 5.56×45 mm M193 round. Comparable results were obtained in the numerical analyses, indicating satisfactory reproduction within the ABAQUS/Explicit simulations. Particular attention was devoted to analyzing the influence of damage parameters – failure displacement and conversion strain – on the residual velocities, as well as on the shape and dimension of material damage for the selected composite configurations. The study contributes to the development of simplified modeling methods for multilayer composites and their calibration in ballistic impact analyses.