Polymer nanocomposite has been a rapidly expanding research topic for producing materials during the last few decades. Over the last two decades, there has been a significant scientific interest in nanoscience and nanotechnology. Nanomaterials' distinct features are related to quantum phenomena, greater surface area, and self-assembly. Quantum effects can begin to dominate matter's behaviour in the nanoscale, particularly at the lower end, affecting optical, electrical, and magnetic properties. Nanomaterials have evolved into nanocomposites with numerous applications. Its applications catapulted them to prominence in the field of material research. Because of their unique property combinations and design practicality, polymer nanocomposites are employed in sports equipment, wastewater treatment, the automobile industry, and biomedical applications. Even though they have numerous advantages, producing them in sufficient quantities and high quality is still one of the biggest challenges. During the last few decades, polymer nanocomposites have been a fast-developing research topic for material production. There has been a surge in scientific interest in nanoscience and nanotechnology during the last two decades. Nanomaterials have developed into nanocomposites, which have a wide range of uses. Its uses propelled them to the forefront of material research. Nanocomposites' physical, mechanical, barrier, flame retardancy, optical, dielectric, rheological, and thermal characteristics have been thoroughly researched. Their uses have also been discussed.