In this work, a new ternary nanocomposite was prepared from polypropylene (PP) as a base and doped with different percentages of nano-cadmium oxide CdO-NPs, and nano-bentonite (Bent. NPs). The ternary nanocomposite was examined as a γ-ray shielding material. The ternary nanocomposite was prepared in the following order 60-PP: (x)CdO: (40-x) Bent. NPs where {x = 0.0, 10.0, 20.0, 30.0 and 40.0 wt%} through the compression molding technique. The structural and morphological characterization of the ternary nanocomposite was carried out using XRD technique. Further, the radiation shielding features of the studied composite material was investigated using Monte Carlo software (FLUKA) for photon energies ranging from 0.015 to 15 MeV. The linear attenuation coefficient (LAC) revealed the addition of CdO NPs enhances the LAC and thus improved the shielding competence of the fabricated nanocomposite. The effective atomic number (Zeff) results showed that the maximum interactions between the photons and the atoms of the samples occurred at 0.122 MeV, and the samples have a good blocking ability to the photons. The results showed that increasing the content of CdO NPs in the composite significantly decreases the half-value layer (HVL) of the used material. The radiation shielding factors examined showed that CdO NPs composite with the percentage of 40 wt% was the superior shield out among of the fabricated Cd-x samples.