A tenement is a type of building that is shared by multiple dwellings, typically with flats or apartments on each floor and with shared entrance stairway access. They are common on the British Isles, particularly in Scotland. In the United States, the term tenement initially meant a large building with multiple small spaces to rent. As cities grew in the nineteenth century, there was increasing separation between rich and poor. With rapid urban growth and immigration, overcrowded houses with poor sanitation gave tenements a reputation as shanty towns. The expression "tenement house" was used to designate a building subdivided to provide cheap rental accommodation, which was initially a subdivision of a large house.

Historically, the word "tenement" meant any permanent residential property used for rental purposes. It could refer to houses, land, and other buildings and the rights attached to this property. In Scotland, the word is still used mainly in this way, primarily when referring to a multi-occupancy building. The word is also used in this way for some legal purposes.

Tenement housing dates back to the growth of the industrial revolution in the 19th century and the sudden influx of people moving to cities. Often narrow, low-rise apartments, the rooms were built "railroad style" which meant rooms without windows and poor ventilation. Many of the properties were overcrowded and lacked indoor plumbing. Today, the term "tenement" refers to an apartment building with multiple dwellings, usually with a few apartments on each floor that all share an entry staircase. However, some people still refer to tenements as a reference to low-income housing units characterized by high-occupancy and below-average conditions.