Sydney is the capital city of New South Wales and the most populous city in Australia. Located on the country's east coast, it is colloquially known as the "Emerald City" or the "Harbour City." The metropolis surrounds Sydney Harbour and extends approximately 80 kilometres from the Pacific Ocean in the east to the Blue Mountains in the west.
The city encompasses 658 suburbs spread across 33 local government areas. It is bordered by Ku-ring-gai Chase National Park and the Hawkesbury River to the north and north-west, and the Royal National Park and Macarthur to the south and south-west. As of June 2025, the city had an estimated population of 5,638,830, representing about 66% of the state's total population.