Vienna is the capital of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.723 million (2.4 million within the metropolitan area, 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 borders of the Czech Republic, Slovakia, and Hungary. These regions work together in a European Centrope border region. Along with nearby Bratislava, Vienna forms a metropolitan region with 3 million inhabitants, and this region is referred to as Twin City. In 2001, the city centre was designated a UNESCO World Heritage Site.

In a 2005 study of 127 world cities, the Economist Intelligence Unit ranked the city first (in a tie with Vancouver, Canada) for quality of life. This assessment was mirrored by the Mercer Survey in 2009 and 2010. Analytically, the city was ranked 1st globally for a culture of innovation in 2007 and 2008, and 2nd globally after Boston in 2009 from 256 cities on an analysis of 162 indicators in the Innovation Cities Index on a 3-factor score covering culture, infrastructure and markets. As a city, Vienna regularly hosts urban planning conferences and is often used as a case study by urban planners.

This city rates highly in popular opinion-based journalistic rankings from magazines such as the Economist Intelligence Unit, whom rated it the second best city in which to live according to their Global Livability Survey in 2011 as well as Monocle, where it is rated 8th among the "Top 25 Livable Cities" in 2010.

The English name Vienna, the official German name Wien, and the names of the city in most languages, are thought to be derived from the Celtic word "windu", meaning bright or fair – as in the Irish "fionn" – 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 Roman settlement Vindobona, probably meaning "white base/bottom," which became Vindovina, Vídeň (Czech) and Wien.

The name of the city in Hungarian (Bécs), Bosnian, Croatian and Serbian (Beč) and Ottoman Turkish (Beç) appears to have a different, Slavonic origin, and originally referred to an Avar fort in the area. In Slovene, the city is called Dunaj, which in other Slavic languages means the Danube River, on which it is located.

Vienna is located in northeastern Austria, at the easternmost extension of the Alps in the Vienna Basin. The earliest settlement, at the location of today's inner city, was south of the meandering Danube while the city now spans both sides of the river. Elevation ranges from 151 to 524 m (495 to 1,719 ft).

Vienna is composed of 23 districts (Bezirke). Administrative district offices in Vienna (called Magistratisches Bezirksamt) serve similar to those in the other states (called Bezirkshauptmannschaft), the officers being subject to the Landeshauptmann (which in Vienna is the mayor); with the exception of the police, which in Vienna is governed by the President of the Police (at the same time one of the nine Directors of Security of Austria), a federal office, directly responsible to the Minister of the Interior.

As had been planned in 1919 for all of Austria but not introduced, the district residents in Vienna (Austrians as well as EU citizens with permanent residence here) are electing a District Assembly (Bezirksvertretung) which chooses the District Head (Bezirksvorsteher) as political representative of the district on city level. City hall has delegated maintenance budgets, e.g., for schools and parks, so that they are able to set priorities autonomously. Any decision of a district can be overridden by the city assembly (Gemeinderat) or the responsible city councillor (amtsführender Stadrat).

The heart and historical city of Vienna, a large part of today's Innere Stadt, was a fortress and surrounded by fields in order to defend itself from potential attackers. In 1850, Vienna with the consent of the emperor included 34 surrounding villages, called Vorstädte, into the city limits (districts no. 2 to 8, since 1861 with the separation of Margareten from Wieden no. 2 to 9). Consequently the walls were razed after 1857, making it possible for the city centre to expand.

In their place, a broad boulevard called the Ringstraße was built, along which imposing public and private buildings, monuments, and parks were created until the turn of the century. These buildings include the Rathaus (town hall), the Burgtheater, the University, the Parliament, the twin museums of natural history and fine art, and the Staatsoper. It is also the location of New Wing of the Hofburg, the former imperial palace, and the Imperial and Royal War Ministry finished in 1913. The mainly Gothic Stephansdom is located at the centre of the city, on Stephansplatz. The Imperial-Royal Government set up the Vienna City Renovation Fund (Wiener Stadterneuerungsfonds) and sold many building lots to private investors, thereby partly financing public construction works.

From 1850 to 1890, city limits in the West and the South have mainly followed another wall called Linienwall. Outside this wall from 1873 onwards a ring road called Gürtel was built. In 1890 it was decided to integrate 33 suburbs (called Vororte) beyond that wall into Vienna by 1 January 1892[22] and transform them into districts no. 11 to 19 (district no. 10 had been constituted in 1874); hence the Linienwall was torn down from 1894 onwards. In 1900, district no. 20, Brigittenau, was created by separating the area from the 2nd district.
From 1850 to 1904, Vienna had expanded only on the right bank of the Danube, following the main branch before the regulation of 1868–1875, i.e., the Old Danube of today. In 1904, the 21st district was created by integrating Floridsdorf, Kagran, Stadlau, Hirschstetten, Aspern and other villages on the left bank of the Danube into Vienna, in 1910 Strebersdorf followed. On 15 October 1938 the Nazis created Great Vienna with 26 districts by merging 97 cities and villages into Vienna, 80 of which have returned to surrounding Lower Austria in 1954. Since then Vienna has 23 districts.

Industries are located mostly in the southern and eastern districts. The Innere Stadt is situated away from the main flow of the Danube, but is bounded by the Donaukanal ("Danube canal"). Vienna's second and twentieth districts are located between the Donaukanal and the Danube River. Across the Danube, where the Vienna International Centre is located, and in the southernmost area are the newest parts of the city (districts 21–23).

Music, theatre and opera
Art and culture have a long tradition in Vienna, including theatre, opera, classical music and fine arts. The Burgtheater is considered one of the best theatres in the German-speaking world alongside its branch, the Akademietheater. The Volkstheater Wien and the Theater in der Josefstadt also enjoy good reputations. There is also a multitude of smaller theatres, in many cases devoted to less mainstream forms of the performing arts, such as modern, experimental plays or cabaret.

Vienna is also home to a number of opera houses, including the Theater an der Wien, the Staatsoper and the Volksoper, the latter being devoted to the typical Viennese operetta. Classical concerts are performed at well known venues such as the Wiener Musikverein, home of the Vienna Philharmonic Orchestra, and the Wiener Konzerthaus. Many concert venues offer concerts aimed at tourists, featuring popular highlights of Viennese music (particularly the works of Wolfgang Amadeus Mozart and Johann Strauss).

In recent years, the Theatre an der Wien has become widely known for hosting premieres of musicals, although it has recently devoted itself to the opera again. The most successful musical by far was "Elisabeth", which was later translated into several other languages and performed all over the world. The Haus der Musik ("house of music") opened in 2000.

The Wienerlied is a unique and very popular song genre from Vienna. There are approximately 60,000 – 70,000 Wienerlieder.

Musicians from Vienna
Many notable musicians were born in Vienna, including: Falco, Franz Schubert, Gerhard Potuznik, Louie Austen, Arnold Schönberg, and Fritz Kreisler.

Museums
The Hofburg is the location of the Schatzkammer (treasury), holding the imperial jewels of the Habsburg dynasty. The Sisi Museum (a museum devoted to Empress Elisabeth Amalie Eugenie of Austria) allows visitors to view the imperial apartments as well as the silver cabinet. Directly opposite the Hofburg are the Kunsthistorisches Museum, which houses many paintings by old masters, ancient and classical artifacts, and the Naturhistorisches Museum.

A number of museums are located in the Museumsquartier (museum quarter), the former Imperial Stalls which were converted into a museum complex in the 1990s. It houses the Museum of Modern Art, commonly known as the MUMOK (Ludwig Foundation), the Leopold Museum (featuring the largest collection of paintings in the world by Egon Schiele, as well as works by the Vienna Secession, Viennese Modernism and Austrian Expressionism), the AzW (museum of architecture), additional halls with feature exhibitions, and the Tanzquartier. The Liechtenstein Palace contains one of the world's largest private art collections of the baroque. Castle Belvedere, built under Prinz Eugen, has a gallery containing paintings by Gustav Klimt (The Kiss), Egon Schiele, and other painters of the early 20th century, also sculptures by Franz Xaver Messerschmidt, and changing exhibitions too.
There are a multitude of other museums in Vienna, including the Albertina, the Military History Museum, the Technical Museum, the Burial Museum, the Museum of Art Fakes, the KunstHausWien, the Sigmund Freud Museum, and the Mozarthaus Vienna. The museums on the history of the city, including the former Historical Museum of the City of Vienna on Karlsplatz, the Hermesvilla, the residences and birthplaces of various composers, the Museum of the Romans, and the Vienna Clock Museum, are now gathered together under the group umbrella Vienna Museum. The museums dedicated to Vienna's districts provide a retrospective of the respective districts.