In May 1787 the first settlers and convicts left Britain for Botany Bay, an area which had been discovered earlier by Captain Cook. On arrival in 1788, the site was found to be unsuitable and the party disembarked further north at Port Jackson, which became Sydney.

Over the years the dependent settlements gradually broke away and gained self-government. New South Wales itself became self-governing in 1855, and continued to exercise control over Queensland until 1859. The Northern Territory was transferred to South Australia in 1863, but New South Wales remained the most influential colony and also provided the base for much of the trading within the Pacific Islands.

In 1901 New South Wales was federated into the Commonwealth of Australia.

Postal History
As early as 1803 there was a postal service operating between Sydney and Parramatta, at a cost of 2d per letter. At this time most of the mail was coming in by private ship and to prevent this being handled privately a 'collecting office' was set up in 1809. This was intended to be solely a distribution centre and it was not until 1825 that an Act was passed which was designed to expand the postal service.

By 1830 a mail-coach service was started from Sydney and this was quickly followed by the establishment of a local twopenny post which operated in the Sydney area.

A new Postage Act was passed by the Governor in 1835 which repealed the 1825 Act and set the rates on the basis of weight and distance travelled. The postmaster, James Raymond, had been pressing for cheaper postage for some time, and had been in correspondence with Rowland Hill to try to make the prepayment of letters between New South Wales and Britain compulsory. This was not approved and, in fact, when he tried to introduce stamps in 1841, after they had been issued in Britain, official objections were raised against the use of stamps in the colonies.

Earlier, in 1838, Raymond had the permission of the Governor to introduce cheaper postage in the local Sydney area. To this end, he produced envelopes with a prepaid embossed stamp showing the seal of the colony. These were considered locally to be the first postage stamps and were commemorated by the colony in 1889 with two special postcards. However, as they were of purely local significance, they have not been accepted as such by philatelists. The usage of these envelopes appears to have been very sparse. They were sold at 1s 3d per dozen as against 2d each for private letters. The public were also allowed to provide their own paper and this could be stamped at a charge of is 8d per 25 impressions. All these showed a marked reduction in cost but the demand remained small. In 1848 stamped covers were recorded as just 15,000 in the year.

By 1838 there were 40 POs in the colony and the 'Ship Letter' Office had been opened in the early 1830s. In 1842 a steamer service was set up between Sydney and Melbourne and in 1844 the first contract mail packet arrived from Britain.

In December 1848 the new Act to reform postage was passed and the first stamps, 'The Sydney Views', were issued on 1 January 1850. The stamps were also available in Victoria until 1853 and Queensland until 1860. At this time there were 97 country POs in addition to Sydney. These were issued with numeral cancellations of two types and the numbers were allocated to the offices as they were opened. By 1852 there were 109 POs.

Stamps of New South Wales were also used in New Hebrides and New Caledonia (q.v.).

New South Wales became a member of the UPU in 1891. It continued to use its own stamps until 1913.