Sydney is the state capital of New South Wales and the most populous city in Australiaand Oceania. Located on Australia's east coast, the metropolis surrounds Port Jackson and extends about 70 km (43.5 mi) on its periphery towards the Blue Mountains to the west, Hawkesbury to the north, and Macarthur to the south. Sydney is made up of 658 suburbs, 40 local government areas and 15 contiguous regions. Residents of the city are known as "Sydneysiders". As of June 2017, Sydney's estimated metropolitan population was 5,131,326, and is home to approximately 65% of the state's population.

Adelaide is the capital city of the state of South Australia, and the fifth-most populous city of Australia. In June 2017, Adelaide had an estimated resident population of 1,333,927. Adelaide is home to more than 75 percent of the South Australian population, making it the most centralised population of any state in Australia.

Melbourne is the capital and most populous city of the Australian state of Victoria, and the second most populous city in Australia and Oceania. Its name refers to an urban agglomeration of 9,992.5 km2 (3,858.1 sq mi), comprising a metropolitan area with 31 municipalities, and is also the common name for its city centre. The city occupies much of the coastline of Port Phillip bay and spreads into the hinterlands towards the Dandenong and Macedon ranges, Mornington Peninsula and Yarra Valley. It has a population of approximately 4.9 million (19% of the population of Australia), and its inhabitants are referred to as "Melburnians".

The city was founded on 30 August 1835, in what was the British colony of New South Wales, by free settlers from the colony of Van Diemen’s Land. It was incorporated as a Crown settlement in 1837 and named in honour of the British Prime Minister, William Lamb, 2nd Viscount Melbourne. It was declared a city by Queen Victoria in 1847, after which it became the capital of the new colony of Victoria in 1851. In the wake of the 1850s Victorian gold rush, the city entered the "Marvellous Melbourne" boom period, transforming into one of the most important cities in the British Empire and one of the largest and wealthiest in the world. After the federation of Australia in 1901, it served as interim seat of government of the new nation until Canberra became the permanent capital in 1927. Today, it is a leading financial centre in the Asia-Pacific region and ranks 20th in the Global Financial Centres Index.

Sydney is the state capital of New South Wales and the most populous city in Australiaand Oceania. Located on Australia's east coast, the metropolis surrounds Port Jackson and extends about 70 km (43.5 mi) on its periphery towards the Blue Mountains to the west, Hawkesbury to the north, and Macarthur to the south. Sydney is made up of 658 suburbs, 40 local government areas and 15 contiguous regions. Residents of the city are known as "Sydneysiders". As of June 2017, Sydney's estimated metropolitan population was 5,131,326, and is home to approximately 65% of the state's population.