New South Wales (abbreviated as NSW) is Australia's most populous state, located in the south-east of the country, north of Victoria and south of Queensland. It was founded in 1788 and originally comprised much of the Australian mainland, as well as New Zealand, Lord Howe Island and Norfolk Island. During the 19th century large areas were successively separated to form the British colonies of Tasmania, South Australia, Victoria, Queensland and New Zealand.

An inhabitant of New South Wales is referred to as being New South Welsh. New South Wales' largest city and capital is Sydney.