A lawn is an area of soil-covered land planted with grasses or (rarely) other durable plants such as clover which are maintained at a short height with a lawnmower and used for aesthetic and recreational purposes. Common characteristics of a lawn are that it is composed only of grass species, it is subject to weed and pest control, it is subject to practices aimed at maintaining its green color (e.g., watering), and it is regularly mowed to ensure an acceptable length, although these characteristics are not binding as a definition. Lawns are used around houses, apartments, commercial buildings and offices. Many city parks also have large lawn areas. In recreational contexts, the specialised names turf, pitch, field or green may be used, depending on the sport and the continent.

The term « lawn », referring to a managed grass space, dates to no earlier than the 16th century. Tied to suburban expansion and the creation of the household aesthetic, the lawn is an important aspect of the interaction between the natural environment and the constructed urban and suburban space. In many suburban areas, there are bylaws in place requiring houses to have lawns and requiring the proper maintenance of these lawns. In some jurisdictions where there are water shortages, local government authorities are encouraging alternatives to lawns to reduce water use.