The Vienna U-Bahn, where U-Bahn is an abbreviation of the German word Untergrundbahn, is a rapid transit system serving Vienna, Austria. The five-line network consists of 83.1 kilometers (51.6 mi) of route, serving 109 stations. It is the backbone of what the International Association of Public Transport (UITP) deemed one of the best-performing public transport systems worldwide in 2009. 459.8 million passengers rode the U-Bahn in 2019. The network is undergoing expansion and rolling stock renewal. Since 1969, 200 million euros have been invested annually in the extension of the Vienna U-Bahn.
Wiener Linien is the company running most of the public transit network in the city of Vienna, Austria. It is part of the city corporation Wiener Stadtwerke.
Wien Mitte is a rail and U-Bahn station in Vienna, close to the city centre. It is the city terminus of Vienna's City Airport Train (CAT), which provides non-stop service to Vienna International Airport. The station is a major hub for S-Bahn suburban trains, with little service by InterCity trains. The station is connected to the Landstraße U-Bahn station.
Line U1 is a line on the Vienna U-Bahn metro system. Opened in 1978, it currently has 24 stations and a total length of 19.3 km (12.0 mi), from Oberlaa to Leopoldau. When the extension to Oberlaa was completed in 2017, the line became the longest on the network, surpassing the length of U6.
Line U2 is a line on the Vienna U-Bahn metro system. Opened in 1980, it currently has 20 stations and a total length of 16.7 km (10.4 mi), from Karlsplatz to Seestadt. It is connected to U1 at Karlsplatz and Praterstern, U3 at Volkstheater, U4 at Karlsplatz and Schottenring.
Line U4 is a line on the Vienna U-Bahn metro system. Opened in 1976, it currently has 20 stations and a total length of 16.5 km (10.3 mi), from Hütteldorf to Heiligenstadt. It is connected to U1 at Karlsplatz and Schwedenplatz, U2 at Karlsplatz and Schottenring, U3 at Landstraße, U6 at Längenfeldgasse and Spittelau.
Spittelau is a station on U4 and U6 of the Vienna U-Bahn. It combines with Wien Spittelau railway station, which is operated by the Austrian Federal Railways (ÖBB), to form a multistorey interchange station.
Hütteldorf is a station on U4 of the Vienna U-Bahn. The U-Bahn station is housed within a train shed at the Wien Hütteldorf railway station, which is also served by long distance and regional trains, and by Vienna S-Bahn lines S45, S50 and S60.
Ober St. Veit is a station on U4 of the Vienna U-Bahn. It is located in the Hietzing District. It opened in 1981.
Unter St. Veit is a metro station on U4 of the Vienna U-Bahn. It is located in the Hietzing District. It opened in 1981.
Braunschweiggasse is a station on U4 of the Vienna U-Bahn. It is located in the Hietzing District.
Hietzing is a station on U4 of the Vienna U-Bahn. It is located beside the canalised Vienna River, on the border of the Viennese districts Hietzing and Penzing, and at the north-western corner of the grounds of the Schönbrunn Palace. It opened as part of the Wiener Stadtbahn in 1898 and became an U-Bahn station in 1981.
Schönbrunn is a station on U4 of the Vienna U-Bahn. It is located in the Hietzing District. It opened as part of the Wiener Stadtbahn in 1898 and became an U-Bahn station in 1981.
Margaretengürtel is a station on U4 of the Vienna U-Bahn. It is located in the Margareten District. It opened as part of the Wiener Stadtbahn in 1899 and became an U-Bahn station in 1980.
Kettenbrückengasse is a station on U4 of the Vienna U-Bahn. It is located in the Margareten District. It opened on the Wiener Stadtbahn in 1899 and became an U-Bahn station in 1980.
Stadtpark is a station on U4 of the Vienna U-Bahn. It is located in the Landstraße District. It opened in 1978.
Roßauer Lände is a station on U4 of the Vienna U-Bahn. It is located in the Alsergrund District. It opened in 1978.
Friedensbrücke is a station on U4 of the Vienna U-Bahn. It is in the Alsergrund District. It opened in 1976.
Wien Heiligenstadt is a railway station located in the Döbling district of Vienna, Austria. Opened in 1898, it is owned and operated by the Austrian Federal Railways (ÖBB), and is served by regional and S-Bahn trains.
Line S45 of the Vienna S-Bahn, also known as the Vorortelinie(lit. Suburban Line) or Wiener Vorortelinie(lit. Vienna Suburban Line), is an electrified commuter rail service operating in Vienna, Austria.
ÖBB: 
, 
, Regionalbahn, REX 
Wiener Linien Bus: 5B, 10A, 11A, 38A, 39A
