The structural, thermal, and optical properties of TiO₂/Polystyrene (PS) nanocompo-siteswere investigated to understand the effects of incorporating rutile-phase TiO₂ na-noparticles. The nanocomposites were synthesized using a solution mixing method followed by hot pressing. Structural analysis, revealed that the crystallite size increased and strain decreased as TiO₂ content increased, indicating a structural evolution. SEM-EDX analysis confirmed uniform distribution of TiO₂ within the PS matrix. Thermal anal-ysis via DSC showed a significant increase in the melting temperature (Tm), rising by up to 41C, reflecting enhanced thermal stability due to restricted polymer chain mobility. TGA results demonstrated improved thermal stability, with a significant shift in decom-position temperatures from 450C for pure PS to 480C for PS/10%TiO₂, highlighting the positive effect of TiO₂ nanoparticles in enhancing the heat resistance of the nano-composites.