Counties in Australia have no administrative or political function, unlike those in England, the United States or Canada. Australia instead uses local government areas, including shires, districts, councils and municipalities according to the state, as the second-level subdivision.
Some other states were also divided into land divisions and land districts; in the nineteenth century, land districts sometimes served as the region name for parts of the state where counties had not been proclaimed yet. Below these are groups of land parcels known as deposited plans, registered plans or title plans (depending on the state). Queensland has registered plans; New South Wales and Western Australia have deposited plans; while Victoria has certified plans. Land can be identified using the number of this plan of subdivision held with the lands department, rather than with a named unit such as a parish (or both can be used); it is becoming increasingly common to use only the plan number. Within these are individual land parcels such as lots; in total there are estimated to be about 10.2 million of these in Australia. The various cadastral units appear on certificates of title, which are given volume and folio numbers; these numbers by themselves are sometimes used to identify land parcels, or in combination with the other units. Detailed maps of these divisions have been required since the introduction of the Torrens title system of a central register of land holdings in South Australia in 1858, which spread to the other colonies. While cadastral data since the 1980s has been digitalised, there remain many old maps showing these divisions held in collections of Australian libraries such as the National Library of Australia, as well as in state libraries.
Counties were used since the earliest British settlement in Australia, with the County of Cumberland proclaimed by Captain Phillip on 4 June 1788. In 1804 Governor King divided Van Diemen's Land into two counties; Buckingham in the south and Cornwall in the north. The parishes date to the surveys conducted after 1825, with the instructions given to Governor Brisbane on 23 Jun 1825 to divide the colony into counties, hundreds and parishes. At this time there were five counties already proclaimed in New South Wales: Cumberland, Westmoreland, Camden, Argyle and Northumberland. The Nineteen Counties in south-eastern New South Wales were the limits of location of the colony in a period after 1829, with the area outside them originally divided into districts, and later also into counties and parishes. Counties were established soon after the foundation of other Australian colonies.
Many of the counties have English names, often the names of counties in England, such as Devon, Dorset, Cornwall and Kent Counties in Tasmania. Less frequently, some have Aboriginal names such as the County of Yungnulgra in New South Wales, and County of Croajingolong in Victoria.
The use of counties, hundreds and parishes was popular in Australia in the 19th century, with many maps of Australian colonies showing these divisions, and towns and cities often listed in their county. Legal cases referenced counties, and many genealogical records for Australia in the 19th century list the county and parish for location of birth, deaths and marriages. The 1911 Britannica also describes Australian towns and cities as being in their respective county, including most of the capital cities: Melbourne, County of Bourke; Sydney, County of Cumberland; Brisbane, County of Stanley; Adelaide, County of Adelaide; and Hobart, County of Buckingham. However it is not mentioned that Perth was located in the County of Perth, as even by this time county names were infrequently used in Western Australia, where they did not cover all of the settled areas, unlike the other states. Instead the system of land divisions and land districts was used, with most of Perth located in the land districts of Swan, Canning and Cockburn Sound, all in the South West Land Division of Western Australia.