Praseodymium-doped antimony–phosphate glasses with the composition 47.5Sb₂O₃–47.5NaPO₃–5WO₃–xPr₆O₁₁ (x = 0.05, 0.1, 0.25, 0.3 mol %) were prepared using the conventional melt-quenching technique to investigate the influence of Pr incorporation on their thermal, structural, physical, elastic, and optical properties. Differential scanning calorimetry (DSC) revealed glass transition temperatures (Tg) between 314.26 and 320.61 °C and thermal stability parameters (ΔT) ranging from 40.12 to 59.07 °C, with the highest stability observed for the undoped glass. FTIR spectra displayed characteristic bands corresponding to P–O–P bending, PO₃²⁻ symmetric stretching, and PO₂⁻ asymmetric stretching, with the intensity of non-bridging oxygen bands increasing with Pr content, indicating network depolymerization induced by Pr₆O₁₁ acting as a network modifier. Density slightly decreased from 4.2735 to 4.2222 g/cm³ with increasing Pr content, while hardness (Hv) showed a steady increase from 254 to 289 Kg/mm². Both molar volume (Vm) and oxygen molar volume (Vo) increased overall with Pr doping, rising from 48.47 to 49.76 cm³/mol and 16.16 to 16.40 cm³/mol respectively. Elastic moduli (longitudinal, shear, bulk, and Young’s) increased with Pr³⁺ content up to 0.25 mol%, indicating improved rigidity and compactness, before decreasing at higher concentrations due to structural relaxation. The optical band gap (Eg) increased slightly from 3.50 to 3.66 eV with doping, while the Urbach energy (E₀₀) remained constant, implying reduced defect states without added disorder. Furthermore, the refractive index increased with Pr content, attributed to greater polarizability and network density. These results suggest that moderate Pr₆O₁₁ doping produces thermally stable, mechanically robust, and optically efficient glasses, making them promising candidates for photonic and optoelectronic applications such as optical amplifiers, lasers, and infrared devices.