This chapter presents a comprehensive analysis of green composites, emphasizing the use of natural fibers and biopolymer matrices as environmentally conscious alternatives to conventional, synthetically reinforced composites. It systematically reviews the mechanical properties, durability, and environmental impact of various green composites, highlighting their suitability for applications such as automotive, civil engineering, packaging, and consumer goods. The chapter examines how fiber-matrix interactions, surface treatments, and processing conditions affect the overall performance of these materials, focusing on factors such as fiber morphology, interfacial bonding, and matrix crystallinity to identify optimal material combinations. It also addresses the challenges associated with green composites, in particular reduced mechanical performance, and discusses strategies for improvement, including hybridization with synthetic fibers and advanced treatments. Current findings indicate that while green composites typically match the properties of traditional composites in many applications, strategic hybridization and ongoing research developments provide pathways to potentially meet or exceed these traditional benchmarks in specific, targeted applications. Such advances support wider adoption in both general and specialized sectors, contributing meaningfully to sustainable practices within the composites industry.