Bioplastics have emerged as sustainable alternatives to conventional petroleumbased plastics, addressing environmental concerns and the need for biodegradable materials. Among these, polyhydroxy butyrate (PHB), a microbial biopolymer, has garnered significant attention due to its inherent biodegradability and biocompatibility. However, the limited thermal stability, high production costs, and intrinsic brittleness of pure PHB pose challenges to its widespread industrial application. Enhancing the physicochemical properties of PHB through blending with other polymers, including synthetic and natural types, represents a viable strategy to overcome these limitations and broaden its applicability. This review provides a comprehensive analysis of microbial strains, metabolic pathways, and fermentation methodologies employed in PHB biosynthesis. It highlights the challenges associated with pure PHB and underscores the critical role of polymer blending techniques in addressing these constraints. The discussion encompasses the mechanical, thermal, and biodegradation characteristics of PHB-based blends, as well as their diverse applications in sectors such as consumer goods, packaging, agriculture, and biomedical fields. Furthermore, the review evaluates the economic and environmental implications of PHB blends, emphasizing their potential as sustainable alternatives to traditional plastics. Emerging advancements, including the incorporation of nanocomposites and innovations in blending technologies, are also explored. The study concludes by delineating current challenges and identifying future research directions, providing insights for the development of highperformance, cost-effective PHB-based bioplastics tailored for practical applications.