Ionizing radiation is vital in various fields but poses health risks, necessitating effective shielding. This study investigated the photon-shielding properties of polyester-based ternary composites with barite (BaSO₄) and tungsten (W) using experimental methods, theoretical calculations, and Monte Carlo simulations for energies between 81 keV and 1332.5 keV. WINXCOM was utilized for the theoretical predictions, and the MCNP6 and PHITS 3.22 algorithms were employed for the simulations. According to the results, the simulation, theoretical, and experimental data all closely aligned. At 81 keV, the composite containing the highest amount of tungsten (PBaW50) had the highest mass attenuation coefficient (3.7498 cm²/g) and linear attenuation coefficient (12.9676 cm⁻¹). Furthermore, for a sample that was 1 cm thick, PBaW50 offered 99.88% protection at 81 keV and had the lowest HVL and TVL values. PBaW50 exhibited attenuation capabilities, making it appropriate for use in industrial, medical, and aerospace settings. In summary, the findings of this study underscore the potential of polyester-based composites doped with barite and tungsten as effective materials for gamma radiation shielding. The PBaW50 sample, in particular, stands out for its attenuation performance, making it a viable option for a wide range of applications where durable and efficient radiation shielding is essential.