This study investigates the radiation shielding properties of Polydimethylsiloxane reinforced with iron in weight fractions ranging from 5–40%. The density of the composite material was calculated using a formula that considers the densities of Polydimethylsiloxane and iron. The mass attenuation coefficient, linear attenuation coefficient, half-value layer, effective atomic number, and equivalent atomic number were calculated using the WinXCom program. The results indicate that the mass attenuation coefficient and linear attenuation coefficient values are higher for low-energy photons, and the composites reinforced with higher weights of iron display higher mass attenuation and linear attenuation coefficients. The contribution of Compton scattering remained almost constant across the energy range, while the photoelectric effect dominated at low energies, and pair production became increasingly dominant at higher energies. The half-value layer decreased as the weight fraction of iron in the composite increased, making composites with a higher weight fraction of iron more efficient at attenuating radiation to a certain level. The effective atomic number and equivalent atomic number values were also higher for composites with a higher weight fraction of iron, indicating that they are more effective at attenuating radiation. Overall, Polydimethylsiloxane reinforced with iron shows promise as a material for radiation shielding applications.