Polyvinyl alcohol (PVA) films doped with Fe2O3-reduced graphene oxide (rGO) nanoparticles (NPs) were prepared using a casting-method. Fe2O3 NPs were synthesized via the hydrothermal process, and then Fe2O3 NPs were decorated on the graphene oxide (GO) sheets, where the GO was transferred to rGO during the sonication process. The obtained films were characterized using XRD and FTIR techniques. Optical absorption and transmission data were recorded via a UV-visible spectrophotometer and used to estimate various optical parameters. Increasing the amount of doped Fe2O3-rGO NPs in PVA decreased the ability of the prepared nanocomposites to allow visible light to pass through them. Solar material protection factor (SMPF) of PVA (11.93%) improved to 99.3%, corresponding to 2 wt% of Fe2O3-rGO NPs doped in the host matrix. The calculated values of the average refractive index are 2.18, 2.25, 2.36, 2.46, and 2.58, corresponding to 0 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, and 2 wt% of Fe2O3-rGO NPs doped in PVA. Therefore, the average refractive index showed a dependence on Fe2O3-rGO NPs. Low energy region (E < 2.4 eV) showed dielectric relaxation time- energy dependent behavior, whereas the high energy region (E > 2.4 eV) displayed dielectric relaxation time- energy independent behavior. Increasing the content of the doped NPs in PVA resulted in lowering the surface and volume energy loss. © 2023 IOP Publishing Ltd.