Novelty architecture, also called programmatic architecture or mimetic architecture, is a type of architecture in which buildings and other structures are given unusual shapes for purposes such as advertising or to copy other famous buildings. Their size and novelty means that they often serve as landmarks. They are distinct from architectural follies, in that novelty architecture is essentially usable buildings in eccentric form whereas follies are non-usable, purely ornamental buildings also often in eccentric form.

Although earlier examples exist, such as the planned but never completed Parisian Elephant of the Bastille, the style generally became popular in the United States, and later to some other countries, as travel by automobile increased in the 1930s. New York City's Statue of Liberty is a statue that is part sculpture and part monument, which like many subsequent examples of novelty architecture, has an accessible interior and became a tourist attraction.

Constructing novelty architecture near to roads became one way of attracting motorists to a diner, coffee shop, or roadside attraction, so buildings were constructed in an unusual shape, especially the shape of the things sold there. "Mimic" architecture became a trend, and many roadside coffee shops were built in the shape of giant coffee pots; hot dog stands were built in the shape of giant hot dogs; and fruit stands were built in the shape of oranges or other fruit. Tail o' the Pup is a hot dog-shaped hot dog stand; Brown Derby is a derby-shaped restaurant; Bondurant's Pharmacy is a mortar-and-pestle pharmacy; the Big Apple Restaurant and the Big Duck are, respectively, a 10.7 metres (35 ft) tall apple and a poultry store shaped like a duck (now a gift shop). Montréal has the restaurant Gibeau Orange Julep built as a 12-metre high orange-coloured truncated sphere in 1966 (replacing its smaller sphere of 1945) and still operating today.

Novelty or programmatic (mimetic) architecture may take the form of objects not normally associated with buildings, such as characters, animals, people or household objects. Lucy the Elephant and The Longaberger Company's head office are examples. There may be an element of caricature or a cartoon associated with the architecture. Such giant animals, fruits and vegetables, or replicas of famous buildings often serve as attractions themselves. Some are simply unusual shapes or constructed of unusual materials.

Many examples of novelty architecture are designed to attract drive-by customers by taking the form of products sold inside. Others, such as casinos in Las Vegas and Macau, are based on famous landmarks from around the world.

Mimetic architecture, or buildings designed to imitate a giant object or creature, sometimes having to do with what is being sold or showcased inside.

Examples include the High-Heel Wedding Church in Taiwan, the Mr. Toilet House in South Korea, the Museum of Tea Culture in China, the National Fisheries Development Board building and the Chowdiah Memorial Hall auditorium in India, the Elephant Building in Thailand, or the Wolfartsweier Cat Kindergarten and the BMW Headquarters in Germany, to name but a few.

Novelty architecture in the form of famous landmarks has been built in China, Georgia, Japan and the United States, for instance. Such replica buildings are extensively used in casinos, hotels, shopping plazas, or amusement parks such as Disneyland where the apparent playfulness and whimsy are intended to add to their appeal. In some cases, such as Carhenge, the structure is an adaptation of a well-known building.