Urban sprawl or suburban sprawl is a multifaceted concept centered around the expansion of low-density development. Topics range from the outward spreading of a city and its suburbs to its logical limits, to low-density and auto-dependent development on rural land, examination of impact of high segregation between residential and commercial uses, and analysis various design features to determine which may encourage car dependency.

Discussions and debates about sprawl are often made unclear by the uncertainty of the meaning associated with the phrase. For example, some commentators measure sprawl only with the average number of residential units per acre in a given area. But others associate it with decentralization (spread of population without a well-defined centre), discontinuity (leapfrog development, as defined below), segregation of uses, and so forth.

The term urban sprawl generally has negative connotations due to the health, environmental and cultural issues associated with the phrase. Residents of sprawling neighbourhoods tend to emit more pollution per person and suffer more traffic fatalities. Sprawl is controversial, with supporters^{[clarification needed]} claiming that consumers prefer lower density neighborhoods and that sprawl does not necessarily increase traffic.