This chapter examines inulin, a naturally occurring polysaccharide renowned for its substantial health advantages and adaptable industrial uses. Inulin is a soluble dietary fiber that is resistant to digestion. It is derived from sources such as chicory root, Jerusalem artichoke, garlic, and onions. Inulin reaches the colon where it is fermented by gut microbiota. Inulin has undergone a historical transformation from a basic carbohydrate to a powerful prebiotic, serving important functions in gut health, weight control, blood sugar regulation, and mental well-being, as evidenced by numerous case studies. Industrially, inulin improves the consistency of food and beverages, provides stability, and acts as a substitute for fat and sugar. It also serves as a functional component in pharmaceuticals and a moisturizing agent in cosmetics. Inulin, which has been approved as safe by regulatory agencies such as the Food and Drug Administration (FDA) and European Food Safety Authority (EFSA), is recommended to be consumed at a daily intake of 10–20 g. Higher doses can be tolerated well if introduced gradually. Ongoing research has revealed the potential of genetic modification and microbial fermentation in improving mineral absorption and promoting mental well-being. These advancements have also led to increased efficiency in production. Novel applications, such as the utilization of 3D-printing technology to create food and the development of synbiotic products, serve to broaden the range of uses for this technology. To summarize, inulin is a versatile ingredient that offers potential health benefits and has a wide range of applications in various industries. It is expected to continue advancing in the future.