The Vienna S-Bahn is a suburban commuter rail network in Vienna, Austria. As opposed to the city-run urban metro network, the Vienna U-Bahn, it extends beyond the borders of the city, is operated by the ÖBB, and consists of many branch lines. S-Bahn is short for Schnellbahn, which can be translated as "rapid railway".

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. 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.