Composite flms with vital multifunctional properties for optoelectronic and varistor applications were prepared via casting procedures. Herein, the present novel composites are based on semi-crystalline polyvinyl alcohol, PVAL, mixed with different contents of Ruthenium-metal. The structure of the flms has been fully identifed through Fourier Transform (FT-IR), difraction analysis of X-ray (XRD), and microscopy of scanning electron (SEM). They confrm signifcant interactions between Ru-metal and PVAL, which leads to a decrease in polymer crystallinity. Ru-metal’s impact on the optical performance has been studied using spectroscopy of UV–Vis–NIR, whereas the applicability of these flms for varistor devices was investigated by measuring the electrical conductivity and I–V curves. The crystallite length (D), the spacing of interplanar (d), dislocation density (δ), internal strain (ε), and separation of interchain (R) parameters were calculated from the measurement of XRD. The active absorption band in FTIR spectra shows a signifcant interaction of Ru-metal with the PVAL via OH groups. The cluster of metal on the composite surface increases with the doping concentration, as illustrated via SEM. Optical bandgaps (Egi & Egd) are estimated from Tauc and absorption ftting (ASF) are nearly equal and reduced with ruthenium addition. Limiting optical absorption (LOA) performance tested using two laser sources showing the reduction of optical transmission via high doping concentration flms. With rising Ru-metal content and frequency, the dielectric and AC conductivity tends to be enhanced. Also, the I-V characteristic was improved, and the conductivity follows the ftting of Jonscher. The collected result refects the consideration of fexible Ru/PVAL as a promising polymeric flm in varistor, micro-optics, optical fbers, and CUT-OFF laser applications.