Traditional natural products have been the focus of research to explore their medicinal properties. One such medicinally important plant is Morus alba, which is growing very quickly, especially in Asia, and has tremendous pharmacological activities due to the presence of phytochemicals in various parts of this plant. In this review, we provide a comprehensive summary of the phytochemistry, biosynthetic pathways, and pharmacological activities of glycoside flavonoids in the leaves of Morus alba has been studied. In the past centuries, mulberry has been considered a food source for silkworms, and its leaves are used to feed animals for livestock. However, in recent years, mulberry has attained a special place in research because of its phytochemical composition and benefits to human health, including antioxidant, anticancer, antidiabetic, and immunomodulatory effects. Phytochemicals are bioactive compounds present in plants that work with nutrients and dietary fiber to protect against diseases. Morus alba also contains many phytochemicals, such as flavonoids, phenols, and anthocyanins. The biosynthetic pathway is greener and more efficient for producing structurally diverse natural products. This pathway acts as an alternative to chemical synthesis and microbial transformation, which suffer from complex routes, difficult isomer separation, and high cost. The mechanism of the flavonoid biosynthesis pathway in mulberry leaves is not yet clear, and currently, this is a much-needed topic for scientists to explore.