The history of the Australian Capital Territory (ACT) as a separate administrative division began in 1911, when the land that would comprise the Territory was transferred from New South Wales to the Australian federal government. The territory contains Australia's capital city Canberra and various smaller settlements. Until 1989, it also administered the Jervis Bay Territory, a small coastal region.

Indigenous Australians have lived in the present-day ACT for at least 20,000 years. The area formed the traditional lands of the Ngambri people and several other linguistic groups. It was incorporated into the Colony of New South Wales with British settlement in 1788, but no white person reached the area until Joseph Wild in 1820. In 1824, Joshua Moore built a homestead named Canberry, whose name was derived from a local Aboriginal language; its meaning is disputed. Further homesteads and stations were established over the course of the 19th century. These were initially large properties used for sheep and cattle grazing, but they were later broken up and subdivided into smaller farms and urban settlements. The oldest gazetted settlement in the ACT is Tharwa, which was proclaimed in 1862.

The Constitution of Australia – which took effect on 1 January 1901 – provided that a new national capital should be built at a site determined by Federal Parliament; (Melbourne served as the temporary capital). It had to be within the state of New South Wales, but at least away from Sydney. The Seat of Government Act 1908 fixed Canberra as the site of the new capital, and the surrounding region was formally ceded to the federal government on 1 January 1911. It was originally known as the Federal Capital Territory (FCT), adopting its current name in 1938. American architect Walter Burley Griffin won the competition to design the new city, and was appointed to oversee its construction. He was dogged by disputes with the government and the onset of World War I, and was fired in 1921. Multiple planning bodies were established but achieved little, in part due to the Great Depression.

Parliament moved to Canberra in 1927, although government offices were slow to follow. The growth of Canberra and the ACT was slow, with potential residents discouraged by the cold winter climate and lack of facilities. Development accelerated after World War II, championed by Prime Minister Robert Menzies who regarded the state of the capital as an embarrassment. The National Capital Development Commission was created in 1957 with more power than its predecessors. It ended four decades of disputes over the shape and design of Lake Burley Griffin, the centrepiece of Canberra, with construction completed in 1964. This prompted the development of the Parliamentary Triangle, a core part of Griffin's design, and followed various buildings of national importance were constructed on the lakefront. On average, the population of Canberra increased by more than 50% every five years between 1955 and 1975. More residential land was released through the creation of new town centres in the 1960s and 1970s.

An elective Advisory Council was created for the ACT in 1930. It was replaced by a House of Assembly in 1974. Full self-government was granted in 1988, with the Legislative Assembly electing the Chief Minister of the Australian Capital Territory to serve as the territory's head of government. The assembly has most of the powers and responsibilities of state governments, but its actions are subject to a federal veto. The ACT gained a seat in the House of Representatives in 1949, initially with limited voting rights. It has had multiple members since 1974, and since 1975 has also elected two members of the Senate.

Indigenous prehistory

Indigenous Australian peoples have long inhabited what is now the ACT. Anthropologist Norman Tindale has suggested the principal group occupying the region were the Ngunnawal people, while the Ngarigo and Walgalu lived immediately to the south, the Wandandian to the east, the Gandangara to the north, and the Wiradjuri to the north-west.

Archaeological evidence from the Birrigai rock shelter in Tidbinbilla Nature Reserve indicates habitation dating back at least 21,000 years. It is possible that the area was inhabited for considerably longer, with evidence of an Aboriginal presence in south-western New South Wales dating back around 40,000–62,000 years. Another site of significance in the reserve is the Bogong Rocks shelter, which contains the oldest evidence of Aboriginal occupation at a bogong moth resting site. These insects were an important source of food for the Aboriginal peoples of the Southern Alps and would accumulate by the thousands in caves and rock crevices, where they were collected and later roasted in sand or ashes, and then eaten whole.

Numerous other culturally significant and archaeologically notable sites are known across the territory, including shelters, rock art sites, stone artefact scatters, scarred trees and chert quarries. Tidbinbilla Mountain is believed to have long been used for Aboriginal initiation ceremonies.

19th-century exploration Following European settlement, the growth of the new colony of New South Wales led to an increasing demand for arable land. Governor Lachlan Macquarie supported expeditions to open up new lands to the south of the capital Sydney, including one to find an overland route to Jervis Bay, an area which would later be incorporated into the ACT as its only coastal possession. In 1818 Charles Throsby, Hamilton Hume, James Meehan and William Kearns set out to find the route, a task accomplished that same year by Throsby and Kearns.

The 1820s saw further exploration in the Canberra area associated with the construction of a road from Sydney to the Goulburn plains, supervised by Throsby and his overseer, Joseph Wild. While working on the project, Throsby learned of a nearby lake and river from the local Aborigines, and he accordingly sent Wild to lead a small party to investigate the site. On 1820, Wild ventured off from his two companions, and later that day arrived at the north shore of what is now known as Lake George. In Governor Macquarie visited the site, and while he was in attendance Throsby decided to push on to reach the river of which he had been informed. Accompanied by Wild and James Vaughan, he journeyed south in search of the Murrumbidgee. The search was unsuccessful, but they did discover the Yass River, and it is surmised that they would have set foot on part of the future ACT.

A second expedition was mounted shortly thereafter, and Throsby's nephew Charles Throsby Smith, Wild and Vaughan further explored the Molonglo (Ngambri) and Queanbeyan (Jullergung) Rivers, becoming the first Europeans to camp at the site. However, they failed to find the Murrumbidgee, and Smith declared that the river did not exist. The issue of the Murrumbidgee was solved in 1821, when Charles Throsby mounted a third expedition and successfully reached the watercourse, on the way providing the first detailed account of the land where Canberra now resides.

The next significant expedition to the region came in 1823, when Wild was employed by Brigade Major John Ovens and Captain Mark Currie to guide them to the Murrumbidgee. They travelled south along the river and named the area now known as Tuggeranong Isabella's Plain, after Isabella Maria Brisbane (1821–1849), the two-year-old daughter of Thomas Brisbane, the then Governor of New South Wales. Unable to cross the river near the current site of Tharwa, they continued on to the Monaro Plains. The last expedition in the region prior to settlement was undertaken by Allan Cunningham in 1824. He reported that the region was suitable for grazing, and the settlement of the Limestone Plains followed immediately thereafter.

Early settlement

When the boundaries for settlement of New South Wales were determined, the Limestone Plains were opened up to settlers. The first land grant in the region was made to Joshua John Moore in 1823, and settlement in the area began in 1824 with the construction of a homestead by his stockmen on what is now the Acton Peninsula. Moore formally purchased the site in 1826 and named the property Canberry, or Canberra, although he never visited it. His claim covered much of the future North Canberra.

Adjacent to the eastern boundary on Moore's claim was the settlement of Duntroon, occupied by James Ainslie on behalf of Robert Campbell. John Palmer was granted land in the region, which was taken up by his son George in 1826. He established Palmerville near Ginninderra Creek in 1829, and the "Squire" at Gungahlin was completed in 1861. Palmerville in the Ginninderra district was the site of the first school in the region, and operated from 1844 to 1848. The first school in the future Canberra opened on the Duntroon Estate, next door to St John's Church in what would become the suburb of Reid in the 20th century. Canberra's first church, St John's, was consecrated and opened for use in 1845.

The Tuggeranong Plains, situated south of the Molonglo River, were first settled in 1827 by Peter Murdoch. The Waniassa Homestead (also known as Tuggeranong Homestead) was established in 1836 by Thomas McQuoid, and the first buildings of the Lanyon estate, owned by John Lanyon and James Wright, were built in 1838. Tharwa was settled in 1834; Moore reportedly identifies two early settlers in the region of Tharwa: William Herbert, a squatter, and George Webb, who later gained a licence in 1937, once they were made available. the homestead in this area was Cuppacumbalong, established by James Wright in 1839. Tharwa is the oldest official settlement in the ACT, having been proclaimed in 1862.

Settlers moved further south into what is now the Namadgi National Park. William Herbert made a claim over part of the Orroral Valley at some point between 1826 and 1836, while during the 1830s Garrett Cotter inhabited what would later be named the Cotter River Valley, in his honour. From the late 1830s, the Boboyan Homestead and station were established. Gudgenby was settled in the early 1840s and the Gudgenby Homestead was erected around this time. By 1848 most of the major valleys of the Namadgi area had been settled.Navin Officer Heritage Consultants (2007), p. 12

Convict labour was widely used in the region, and the first bushrangers in the area were runaway convicts. John Tennant, the earliest and best-known bushranger of the region, lived in a hideout on what is now known as Mount Tennant, behind Tharwa. From 1827 he raided the local homesteads, stealing stock, food and possessions until his arrest in 1828; he was later hung in Sydney for his crimes. The lawlessness of the region led to the appointment of the first resident magistrate on 1837 – Allured Tasker Faunce, who was also known as "Ironman Faunce" since his time as a magistrate at Brisbane Water. The magistrate oversaw legal matters and issued liquor licences to several establishments, the first being the Elmsall Inn on the Duntroon estate in 1841.

A significant influx of population and economic activity occurred around the 1850s goldrushes, particularly the Kiandra rush of 1859–60. The goldrushes prompted the establishment of communication between Sydney and the region by way of the Cobb & Co coaches, which transported mail and passengers. The first post offices opened in Ginninderra in 1859 and at Lanyon the following year. Bushranger activity continued with the goldrushes: Australian-born bandits Ben Hall and the Clarke brothers were active in the area, targeting mail coaches and gold transportation.