in merchandising, a retail store that sells products at prices lower than those asked by traditional retail outlets. Some discount stores are similar to department stores in that they offer a wide assortment of goods; indeed, some are called discount department stores.

Others specialize in such merchandise as jewelry, electronic equipment, sporting goods, or household appliances. Discount stores that specialize in a specific assortment of goods within a retail category are called “category killers.” Examples of these include Toys “R” Us for toys, IKEA for home furnishings, Staples for office products, and Home Depot for hardware and construction materials. These stores carry a variety of national brands (usually purchased directly from the manufacturers) while offering low prices and knowledgeable service. Stores that are open only to certain groups, such as members of cooperatives or government employees, are often known as closed-door discount stores.

Originating largely in the United States, discount stores have spread worldwide, notably to western Europe, Latin America, Australia, and Japan. Discount store operator Wal-Mart Stores, Inc., which opened its first international outlet in Mexico City in 1991, had become the world's largest retailer by the end of the 20th century.