Milk osteopontin, a multifunctional phosphorylated glycoprotein derived from milk, plays significant roles in immune regulation, as well as promoting brain development and cognitive function, intestinal health and bone health, and it is recognized as a novel ingredient for infant formula and related food products. With the aim of providing a reference for the development and utilization of milk osteopontin, this article systematically elaborates on recent advancements in its structural characteristics, digestion, absorption and nutritional functions, and discusses its future application prospects and research directions as a novel food ingredient.