Chitosan is widely used in the agricultural sector as a natural biostimulant and elicitor, enhancing plant growth and improving resistance to diseases. It is applied as a seed coating or foliar spray to boost crop yield and quality. In the food industry, it serves as an edible film or coating to extend the shelf life of fruits, vegetables, and seafood by acting as a barrier to moisture and microbes. It is also utilized as a natural preservative due to its antimicrobial properties and as a viscosity enhancer. In nutraceutical applications, chitosan is incorporated into dietary supplements to help reduce cholesterol absorption and aid in weight management through its fat-binding properties. In water treatment, chitosan is effective in removing heavy metals, dyes, and other pollutants from wastewater due to its chelating and flocculating abilities. In the medical field, it is used in wound healing products, drug delivery systems (including controlled-release encapsulation and transdermal patches), and tissue engineering scaffolds because of its biocompatibility, biodegradability, and antimicrobial activity. Additionally, chitosan is employed in cosmetics and personal care products for its moisturizing, film-forming, and skin-repair stimulating properties, improving skin and hair health.