An anchor store is a large retail store found incorporated into a shopping mall or other commercial structure alongside other, smaller retailers. Its purpose in this role is, as the name suggests, to "anchor" the mall and support the other stores by drawing a high volume of consumers and establishing the location as a viable and attractive shopping destination. Originally, mall anchor stores were almost inevitably traditional department stores like Sears or JCPenney, though in recent decades, discount stores like Kmart and Target have become more common, and the "big box" category killer stores like Home Depot or Best Buy which met with such success in the 1990s and late 1980s have also begun to take on this role, as many department store chains have collapsed and the format itself is increasingly appearing obsolete. Ironically, many blame this industry development precisely on the early success of department stores in an anchor role, establishing the large, geographically isolated suburban mall as a viable business model and creating an environment in which narrowly tailored "boutique" chain stores could flourish.

Conventional wisdom holds that a mall requires at least two anchor stores to be successful, and in the standard linear, bipolar mall design, one of these stores will be located at each end, so that shoppers traveling from one to the other will traverse the entire length of the mall, passing by the rest of the stores found within. If a mall contains more than two of these anchors, they are likely to be found as "spurs" off of the central mall concourse, or at least located in their own recessed "courts", rather than opening directly onto the main traffic pattern. Anchor stores are often the only stores in a mall to have their own external facades, signage and entrances, and indeed, building and parking lot layout are frequently designed to encourage mall shoppers to enter and pass through these stores in order to reach the mall proper. In multi-floor malls, anchor stores often extend vertically for multiple shopping levels tied together with elevators and escalators (plus possibly basement loading docks and stockrooms), although this might be considered a holdover from traditional, standalone department store design and is less commonly found in other types of anchors.

Anchor stores can also be found in open-air, street-fronting shopping centers, where they operate along much the same principles, although department stores are far less common in this format, their place being taken by supermarket grocery stores. Indeed, the existence of such anchor stores, along with the closely related issues of building and parking lot size, is one of the primary criteria on which the "shopping center" is distinguished from the "strip mall", the latter carrying more negative connotations and usually considered a less attractive and less prestigious location from the perspective of both consumers and retailers.