Kmart (often spelled as "K-Mart") is a chain of department stores in the United States, Puerto Rico, the U.S. Virgin Islands, and Guam. The chain merged with Sears in 2005, creating the Sears Holdings Corporation. Kmart also exists in Australia and New Zealand (see Kmart Australia), although it now shares no current relation with the American stores except in name after US equity in the Australian business was purchased in the late 1970s. It is the third biggest discount store chain in the world, behind Wal-Mart and Target.

Sebastian S. Kresge, who had previously founded the S. S. Kresge dime store chain, opened the first Kmart store in 1962 in Garden City, Michigan and named Kmart after himself; this store is still in operation to this day. A total of eighteen Kmart stores opened that year. Kmart Foods, a now defunct chain of Kmart supermarkets, opened in that same decade.

Kmart's world headquarters was located in Troy, Michigan in a sprawling complex which, since Kmart's relocation to Illinois, has been slated for demolition blank">http://www.detnews.com/apps/pbcs.dll/article?AID=/20070501/METRO/705010382.

Kmart became known for its "Blue Light Specials." They occurred at surprise moments when a store worker would light up a mobile police light and offer a discount in a specific department of the store. The phrase "attention Kmart shoppers" also entered into the American pop psyche.

During the 1970s, Kmart put a number of competing retailers out of business. In 1977, S. S. Kresge Corporation changed its name to Kmart Corporation. In 1987, the Kmart Corporation sold its remaining Kresge and Jupiter stores in the United States to _McCrory Stores, although Canadian Kresge stores continued to operate until 1994.