New glasses with enhanced radiation shielding characteristics have potential applications in different fields requiring radiation protection. In the context of radiation shielding applications, this work aims to develop new lead-free B2O3–TeO2–Bi2O3–ZnO–CaO glass systems. A 15–30 mol% increase in TeO2 concentration results in a 4.070–4.498 g/cm3 density increase. The influence of increasing the TeO2 doping concentration on the mechanical properties of the prepared boro-tellurite glass was utilized using the Makishima-Makinze theory. Additionally, the influence of raising the TeO2 concentration on the radiation shielding properties of the prepared boro-tellurite glass was studied using the Monte Carlo simulation. The Monte Carlo simulation confirms that a 15–30 mol% TeO2 increase enhances LAC values, reducing half-value layer thickness (HVL), and improving radiation shielding. However, mechanical properties such as hardness and Young's modulus slightly decrease due to TeO2 substitution.