Biscuits are a global snack due to their convenience, variety, and durability. Biscuits with nutritious ingredients are in demand as customers become more health conscious. This change led to interest about utilizing agricultural by-products to enhance the nutritional value of widely consumed foods. Mango (Mangifera indica L.), a frequently cultivated tropical fruit, produces vital by-products during its processing, mainly comprising peels and kernels. The by-products, comprising around 35–60% of the mango fruit's weight, are high in bioactive compounds including dietary fiber, polyphenols, carotenoids, and essential fatty acids. Mango peels and kernels, even with their nutritional potential, frequently neglected, resulting in rising environmental waste. This study examines how mango peels and kernels can boost biscuits' nutritional fiber and antioxidant content. Researchers synthesize mango by-product nutritional and functional benefits and extraction and processing technologies. The study also examines mango by-products' sensory and economic effects on biscuits. High fiber and antioxidant content in mango peel powder improve digestion and reduce oxidative stress. With its beneficial fats and polyphenols, mango kernel powder adds nutrition. Health-conscious consumers may choose biscuits with 5–15% mango by-products since they retain or increase flavor, texture, and color. By-products from mangoes reduce food waste and promote a circular economy. Commercial application requires optimizing processing procedures, product quality consistency, and clinical trials to validate health claims. According to this analysis, mango by-products can enable creative and sustainable food production and meet customer demand for health-focused goods.