Tamarind (Tamarindus indica L.) seed polysaccharide (TSP), whose main component is xyloglucan, is described in this review as a promising biopolymer for various food applications on the basis of its properties. TSP consists of relatively stiff rod-like molecules with multistranded lateral self-aggregation between these molecules, and TSP has no conformational transition. TSP has structural properties that are intermediate between those of single chain polysaccharides such as galactomannan and helix-form polysaccharides such as xanthan gum. These properties include characteristic solution fluidity regarded as Newtonian, unique gelling properties, and the emulsifying effects of TSP. In practice, TSP has been used for various functions. Food categories in which TSP plays an important role in more beneficial functions, such as in bakery products, dressings and mayonnaise, and frozen desserts, are the focus of this article. Here, the effects and mechanisms of TSP are also proposed based on accumulated findings and recent practical use.