Vienna is the capital of the Republic of Austria and also one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.7 million (2.3 million within the metropolitan area which means more than 25% of Austria's population), and is by far the largest city in Austria, as well as its cultural, economic, and political centre. It is the 10th largest city by population in the European Union. Vienna is host to many major international organizations such as the United Nations and OPEC. Vienna lies in the east of Austria and is close to the Czech Republic, Slovakia and Hungary. In 2001, the city centre was designated a UNESCO World Heritage Site and in 2005 an Economist Intelligence Unit study of 127 world cities ranked it first equal with Vancouver for the quality of life. This assessment was mirrored by the Mercer Survey in 2009.

The English names of Vienna, the official German name Wien, and the names of the city in most languages, are thought to be derived from the Celtic name of a settlement, but opinions vary on the precise origin. Some claim that the name comes from Vedunia, meaning "forest stream", which subsequently became Venia, Wienne and Wien. Others claim that the name comes from the name of the Roman settlement Vindobona, probably meaning "white base/bottom", which became Vindovina, Viden and Wien.