The Warsaw-Vienna Railway (Polish: Kolej Warszawsko-Wiedeńska, German: Warschau-Wiener Eisenbahn) was a railway system which operated in Congress Poland, a part of the Russian Empire, from 1845 until 1912, when it was nationalized by the Russian government. The main component of its network was a line 327.6 km in length from Warsaw to the Granica (English: Border) station (today Maczki, located in a suburb of Sosnowiec) on the border with the Austrian Empire, from 1867 known as the Austro-Hungarian Empire. There the line reached the Austrian railway network, offering connections i.a. to Vienna (hence the name of the line). It was the first railway line built in Congress Poland and the second in the Russian Empire, after a short stretch of 27 km between Tsarskoye Selo and Saint Petersburg (Saint Petersburg - Tsarskoe Selo Railway) which opened in 1837. The line used the standard European gauge (1,435 mm (4 ft 8 1⁄2 in)), as opposed to all other railways in the Russian Empire which used the broad gauge (1,524 mm or 5 ft), hence it formed a system physically separated from other Russian railways.
The first concrete plan to build a railway between Warsaw and the southern border of the Congress Poland was submitted to Bank Polski (Polish Bank) in January 1835. Three years later, in 1838 Towarzystwo Akcyjne Drogi Żelaznej Warszawsko-Wiedeńskiej (Warsaw-Vienna Rail Road Company Ltd) was established and granted a licence to build the railway. Arguments between proponents of horse and steam traction lasted many years, and only in 1840 the latter was chosen when the building work started. The company went bankrupt in 1843 and was taken over by the state. In 1857 the line was leased to a private company (also called Towarzystwo Akcyjne Drogi Żelaznej Warszawsko-Wiedeńskiej) for 75 years, however it was re-nationalised in 1912, with a compensation paid to the shareholders (mostly Belgians and Germans).