In the present work, polyvinyl alcohol (PVA) films were prepared for polymer optoelectronic applications, in which the SiO2 nanoparticles were incorporated through a sonication technique followed by a solution casting method. The structure of PVA/SiO2 films was evaluated using the experimental results attained by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscope (SEM) examinations. A thermal stability study of the nanocomposite films was performed. UV-vis spectra were used to investigate the optical properties of PVA/SiO2 nanocomposite films. The XRD results confirmed the semicrystalline nature of the PVA. The SEM results ascertained the homogeneity of the SiO2 nanoparticles in the polymer matrix. From the study, a simultaneous increase of SiO2 nanoparticle content decreased the direct optical band gap and Urbach energy; however, the refractive index and extinction coefficient were increased. The acquired nanocomposite films could be utilized in polymer optoelectronic applications.