In this study, novel Al₆₀₆₁-(30-x)B₄C-xSm₂O₃ (x = 0, 1, 3, 5, 7, and 9 wt%) composites were fabricated using high-energy ball milling followed by cold pressing and sintering. The aim was to improve both the mechanical performance and radiation-shielding capabilities by integrating Sm₂O₃ as a reinforcement phase. Microstructural analyses via XRD and SEM-EDX revealed that the addition of Sm₂O₃ significantly enhanced phase uniformity, reduced porosity, and improved interfacial bonding, especially by mitigating the inherent poor wettability between Al₆₀₆₁ and B₄C. As a result, the relative density, hardness, and wear resistance were considerably improved with an increasing Sm₂O₃ content. Monte Carlo simulations (MCNP6.2) demonstrated that while thermal neutron shielding showed a slight decline due to the reduced boron content, fast neutron and gamma-ray attenuation were substantially enhanced owing to the high atomic number and density of Sm₂O_3. The results demonstrate that the mechanical performance and superior neutron-shielding properties contribute to new visions in material design and applications and have the potential to provide safer and more effective radiation-protection solutions that are environmentally sustainable.