Nanocomposites of chitosan (Cs)/polyacrylamide (PAM) with synthesized selenium nanoparticles (SeNPs) were prepared via casting technique. The effects of SeNPs on the structural, optical, and electrical properties of the synthesized Cs/PAM/SeNPs nanocomposites samples were characterized. The XRD and FT-IR spectra confirmed the intermolecular interactions between selenium nanoparticles and Cs/PAM blend. Moreover, the decrease in the values of the optical energy gaps confirms the presence of SeNPs dispersed in the Cs/PAM samples. The transmission electron microscopy (TEM) image showed that synthesized SeNPs have sizes ranging from 42 to 57 nm. Scanning electron microscopy (SEM) showed the complexation between the polymeric matrix and the SeNPs. The AC conductivity of the polymeric samples was improved after the addition of SeNPs. The values of the complex permittivity of the nanocomposite samples showed increase with increasing concentration of SeNPs, which is due to increase in the ionic conduction of the samples. The present results showed the advantage of using SeNPs as nanofiller to improve the optical and electrical properties of Cs/PAM samples. Therefore, this obtained results in this work demonstrated that the Cs/PAM/SeNPs polymeric samples seem to be a promised candidate as an electrolyte cum separator for energy storage devices.