Mobile homes (in the United States; also called trailers or house trailers) or static caravans (in other countries; also called caravans) are prefabricated homes built in factories, rather than on site, and then taken to the place where they will be occupied. Being built on a permanently attached chassis with highway-grade wheels and tires, they are usually transported by being pulled behind a tractor-trailer over public roads to a home site. Mobile homes share the same historic origins as travel trailers, but today the two are very different in size and furnishings, with travel trailers being used primarily as temporary or vacation homes.

Mobile homes are usually placed in one location and left there permanently, but they do retain the ability to be moved, as required in many areas. Behind the cosmetic work fitted at installation to hide the base, there are strong trailer frames, axles, wheels, and tow-hitches.

In the United States, this form of housing goes back to the early years of cars and motorized highway travel. It was derived from the travel trailer, a small unit with wheels attached permanently, often used for camping or extended travel. The original rationale for this type of housing was its mobility. Units were initially marketed primarily to people whose lifestyle required mobility. However, beginning in the 1950s, the homes began to be marketed primarily as an inexpensive form of housing designed to be set up and left in a location for long periods of time, or even permanently installed with a masonry foundation. Previously, units had been eight feet or less in width, but in 1956, the 10-foot (3 m) wide home ("ten-wide") was introduced, along with the new term "mobile home".