Sydney is the capital city of the state of New South Wales, and the most populous city in Australia and 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, the Royal National Park to the south and Macarthur to the south-west. Sydney is made up of 658 suburbs, spread across 33 local government areas. Informally there are at least 15 regions. Residents of the city are known as "Sydneysiders". As of June 2020, Sydney's estimated metropolitan population was 5,367,206, meaning the city is home to approximately 66% of the state's population.

Despite being one of the most expensive cities in the world,Sydney frequently ranks in the top ten most liveable cities in the world.It is classified as an Alpha Global City by Globalization and World Cities Research Network, indicating its influence in the region and throughout the world Ranked eleventh in the world for economic opportunity, Sydney has an advanced market economy with strengths in finance, manufacturing and tourism.There is a significant concentration of foreign banks and multinational corporations in Sydney and the city is promoted as Australia's financial capital and one of Asia Pacific's leading financial hubs Established in 1850, the University of Sydney was Australia's first university and is regarded as one of the world's leading universities.Sydney is also home to the oldest library in Australia, the State Library of New South Wales, opened in 1826.

Sydney has hosted major international sporting events such as the 2000 Summer Olympics. The city is among the top fifteen most-visited cities in the world,with millions of tourists coming each year to see the city's landmarks Boasting over 1,000,000 ha (2,500,000 acres) of nature reserves and parks, its notable natural features include Sydney Harbour, the Royal National Park, Royal Botanic Garden and Hyde Park, the oldest parkland in the country. Built attractions such as the Sydney Harbour Bridge and the World Heritage-listed Sydney Opera House are also well known to international visitors. The main passenger airport serving the metropolitan area is Kingsford-Smith Airport, one of the world's oldest continually operating airports Established in 1906, Central station, the largest and busiest railway station in the state, is the main hub of the city's rail network