High-Density Polyethylene (HDPE) stands out as a versatile thermoplastic polymer derived from the monomer ethylene, showcasing a remarkable array of applications ranging from household appliances and automobiles to wiring, cables, aeronautics, and packaging. Despite its widespread use, HDPE encounters limitations attributed to its suboptimal weather resistance. Addressing these challenges becomes imperative to enhance HDPE properties and cost-effectiveness. This review explores the incorporation of various fillers, such as natural fibers, sisal fibers, Kenaf fibers, and back fibers, with HDPE to overcome its drawbacks. The integration of fillers aims to optimize HDPE characteristics, rendering it suitable for an even broader spectrum of applications. One promising filler is Rice Husks (RH), an abundant byproduct of the rice milling process, constituting approximately 20% of rice paddy. Comprising cellulose, lignin, silica, and moisture, RH offers a unique composition that can potentially enhance the mechanical and thermal properties of HDPE. The low commercial value of rice husks, coupled with the undesirable outcomes of burning them for energy extraction, prompts exploration into their application as fillers for thermoplastic polymers. The literature reveals a growing interest in utilizing rice husk ash, a byproduct of burning rice husks, as an effective filler in thermoplastic polymers. This approach not only addresses the environmental concerns associated with rice husk disposal but also enhances the value proposition of the resulting composite materials. The review encompasses studies on the properties of HDPE composites reinforced with rice husk ash, shedding light on the impact of geographical conditions, rice variety, sample preparation methods, and analysis techniques on the composite's characteristics. By capitalizing on the abundance of rice husks and their potential contribution to improving HDPE properties, this review advocates for sustainable and economically viable solutions. The utilization of rice husk ash as a filler in HDPE presents an opportunity to simultaneously address environmental challenges related to rice husk disposal and enhance the performance and cost-effectiveness of HDPE-based materials. Through a comprehensive exploration of the literature, this review contributes valuable insights into the diverse applications and advantages of incorporating rice husk-derived fillers in HDPE composites.