Animal-derived biopolymersAnimal-derived biopolymers constitute a versatile group of materials that are naturally produced and have gained increasing attention for their remarkable biodegradabilityBiodegradability, biocompatibility, and sustainable nature. These polymers, including chitin, chitosan, collagen, gelatin, silk fibroin, keratin, elastin, hyaluronic acid, and resilin, are primarily extracted from biological byproducts such as crustacean shells, animal hides, feathers, and connective tissues. Their structural and functional properties make them appropriate for a wide range of applications in biomedicine, pharmaceuticals, environmental management, and packaging industries. This chapter explores the journey of these biopolymers, beginning with their chemical composition, physical and biological properties, raw material sources and extending to their development processes. Along with traditional methods of extraction and purification, ecofriendly and scalable methods such as enzymatic treatments, supercritical CO₂ extraction, ion exchange chromatography and membrane-based purification have been mentioned that enhance the purity and performance of the biopolymers while minimizing environmental impact. The multifunctionality of these materials is highlighted through their roles in tissue engineering, antimicrobial systems, drug delivery, and wound healing. Although these materials offer promising alternatives to synthetic polymers, challenges remain in terms of source variability, immunogenicity, and regulatory acceptance. Continued advancements in biotechnology, recombinant protein synthesis, and green chemistry are expected to expand their applicability and economic viability. Overall, animal-derived biopolymersAnimal-derived biopolymers represent a sustainable platform for next-generation material science and innovation, fostering a circular bioeconomy.