Titanium oxide nanobelts (TiO2 NBs) are successfully prepared by hydrothermal method in alkaline medium. The surfaces of the obtained NBs were modified to become hydrophobic character. Commercial polystyrene was loaded with different ratios of the aforementioned hydrophobic TiO2 NBs. The casted films were characterized using thermal gravimetric analysis (TGA) and mechanical testing, and their morphology was studied by TEM. The mechanical properties of the prepared PS/TiO2 NBs composite were evaluated and found to be enhanced by increasing the loading of TiO2 NBs. Correspondingly, the antibacterial testing was performed against representative strains of Gram-positive and Gram-negative bacteria. The results showed that the prepared nanocomposite can be used as packaging materials.