In the current research, synthesized Se-NPs were loaded into sodium alginate/polyvinyl alcohol SA/PVA blend, 1:2 (w:w), with different proportions to form nanocomposite films by using the solution casting method. The main goal is to enhance the physical and antibacterial properties of the polymer blend; therefore, it can be utilized for wound dressing applications. The physical aspects of the prepared films were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), atomic force microscope (AFM), scanning electron microscope (SEM), Energy dispersive X-ray (EDX), UV–Vis spectro- scopic technique, and mechanical analysis to show the effect of increasing the concentration of Se-NPs from zero to 0.5 wt% on their properties. Regarding the XRD analysis, the calculated values of lattice strain (𝜀) increased from 0.005 to 0.013. The FTIR absorption spectrum recorded an intensity reduction and position shift in the main characteristic peaks of SA/PVA. The morphology of Se-NPs revealed a spherical shape with a mean diameter of 131.76 nm, as revealed by transmission electron microscopy (TEM). The surface morphological images showed the appearance of a few cracks; besides, the average rough- ness increased from 1.59 to 2.08 nm. According to the UV–Vis spectroscopic analysis, the optical band gap reduces (from 5.425 to 5.216 eV) for the direct transition and from (5.07–4.78 eV) for the indirect transition, which is an indication of the interaction between Se-NPs and SA/PVA blend. Young’s modulus, tensile strength, and yield strength of the films increased with the addition of selenium nanoparticles. On the other hand, the amount of selenium release significantly increased with enhancing the concentration of Se-NPs in SA/PVA blend film from 0.1 to 0.5 wt%. Additionally, the inclusion of Se-NPs supplied the polymer blend with excellent antimicrobial activity, which would remove the possibility of microbial infection at the wound site. Moreover, the prepared SA/PVA/Se nanocomposite films have good biocompatibility with Human Skin Fibroblast (HSF). The results suggest the potential of this nanocomposite to be used in wound dressing applications.