Cairnlea is a residential suburb that was begun by the Urban Land Corporation in the late 1990s. It is on the land formerly known as the Albion Explosives site in Deer Park, 17 km north-west of Melbourne and immediately north-west of the intersection of Ballarat Road and the Western Ring Road.

The suburb is an infill development in the sense that there was pre-existing urbanisation on its boundaries: the Brimbank Central shopping centre on its west was opened in 1979, and St Albans on its east was developed earlier.

The Corporation’s plan (1999) for the suburb included about 2900 house lots, neighbourhood shops, a primary school and provision for new offices for the Brimbank council. About 30% of the suburb’s area of 460 hectares was reserved open space, including 35 hectares of grassland with restricted access for the preservation of endangered species such as legless lizard and the plains rice flower.

The name ‘Cairnlea’ was derived from the topography: ‘cairn’ refers to a monument of loose stones, a reference to the lava rocks that have been used to built rural fences, and ‘lea’ refers to open meadows or grassland. Jones Creek flows south-east through Cairnlea, and has a linear parkland and a birdlife habitat. There is also a reserve along the Kororoit Creek in the south of Cairnlea.

The first house lots were offered for sale in February, 1999. By 2012 most lots were built on, and the only large vacant areas were a proposed business precinct near the Ring Road and land reserved for a secondary college.

Cairnlea has a drive-in shopping centre (supermarket plus 33 outlets), a community centre, a recreation reserve and two kindergartens. The primary school (2009) (879 pupils, 2014) replaced the Deer Park State school which was at the corner of Ballarat and Station Roads. The Victorian Croquet Club’s headquarters are at Cairnlea. Albion Explosives is marked by the heritage listed gunpowder mill (1939) in Parklea Avenue.

Cairnlea’s census populations have been:

census date population
2001 not stated
2006 6070
2011 8839

At the 2011 census, English was the spoken language at home for only 25.5% of residents and Vietnamese was spoken by 25.9% of residents. The median income of residents was 99% of the Victorian median; in Deer Park it was 84% (2011 census).