Ultraviolet (UV) radiation, a form of energy from the Sun, poses health risks, prompting the development of materials capable of blocking it. These materials, known as UV absorbers, are classified as organic (e.g., salicylates, cinnamates, avobenzone) or inorganic (e.g., TiO₂, ZnO, MnO₂). UV radiation also originates from artificial sources like mobile screens and LEDs, increasing the need for protective measures. In response, a thin film was developed using polyvinyl alcohol (PVA) and a PVA-MnO₂ nanocomposite, prepared via solution casting. PVA’s biodegradable and non-toxic nature makes it a versatile material for such applications. To enhance UV protection, a natural pigment, flavonoid, was incorporated into the film. Characterization using a UV-visible spectrophotometer revealed that the PVA-MnO₂ film with 2wt% flavonoid achieved high UV absorption (92%) but reduced visible light transparency (45%). Such films are ideal for window applications in regions with intense sunlight exposure, including areas near the equator, the Middle East, Southeast Asia, Africa, and Australia, offering a promising solution for safeguarding human health against UV radiation.