<p>Chitosan, a naturally occurring biopolymer derived from chitin, has gained immense attention due to its biocompatibility, biodegradability, and functional versatility. However, its limited solubility and processability restrict its potential in various applications. Graft copolymerization has emerged as a powerful strategy to chemically modify chitosan, enhancing its physicochemical properties by introducing diverse monomeric structures. This review comprehensively explores the graft copolymerization of chitosan, highlighting key initiation systems including ceric ammonium nitrate (CAN), persulfate-based, and ferric ion-based redox systems. Furthermore, the review emphasizes the applications of chitosan graft copolymers.</p>