AbstractSemi‐interpenetrating polymer networks (SIPNs) have garnered significant interest due to their potential applications in self‐healing materials, drug delivery systems, electrolytes, functional membranes, smart gels and, toughing. SIPNs combine the characteristics of physical cross‐linking with advantageous chemical properties, offering broad application prospects in materials science and engineering. This perspective introduces the history of semi‐interpenetrating polymer networks and their diverse applications. Additionally, the ongoing challenges associated with traditional semi‐interpenetrating polymer materials are discussed and provide an outlook on future advancements in novel functional SIPNs.