The Austrian Northwestern Railway (German Nordwestbahn) was the name of a former railway company during the time of the Austro-Hungarian monarchy. Today, the term is still used (although only rarely) to refer to the railway line which was formerly operated by that company.

The privately owned Nordwestbahn took over the branch of the Nordbahn from Floridsdorf to Stockerau in 1841 and extended it in 1871 via Hollabrunn and Retz to Znaim (Moravia). It was nationalized in 1908 and subsequently lost its significance. Vienna Northwest Station was closed down in 1924 and has only been used for freight transports since World War II. The bridge used by the company was transformed into an Autobahn bridge during the 60s. Passanger service between Retz and Znaim was reopened in 1990.