Chitin is a highly adaptable natural biopolymer that can be chemically modified into a variety of derivatives through physical, chemical, and enzymatic processes. These modifications result in derivatives with distinct properties, each offering unique potential for application across diverse industries, including food, agriculture, pulp and paper, cosmetics, toiletries, environmental management, pharmaceuticals, and biomedicine. Recent advancements in nanomaterial science have further expanded the scope of chitin research, leading to the development of chitin-based nanomaterials with innovative applications. In the field of therapeutics, chitin and its derivatives have shown significant promise. They have been explored for their potential in wound healing, anti-inflammatory treatments, cancer therapy, diagnostic tools, antimicrobial agents, and immunomodulation. This chapter provides an insight into various chitin derivatives and their roles in therapeutic applications, highlighting their diverse and versatile functionalities.