The U1 is an underground line in Nuremberg. The first part of the line was opened on 1 March 1972. It is about 18.5 kilometres (11.5 mi) long and has 27 stations. The termini are Langwasser Süd in the southeast and Fürth Hardhöhe in the northwest. Until 11 December 2016 it shared tracks with the former booster line U11 between Eberhardshof and Messe. Those services are still run but no longer designated U11, instead being signed U1 like trains doing the full Langwasser-Hardhöhe run. Unlike U2 and U3 all trains are operated by a driver and there are no plans to automate U1.

The Nuremberg U-Bahn is a rapid transit system run by Verkehrs-Aktiengesellschaft Nürnberg, which itself is a member of the Verkehrsverbund Großraum Nürnberg. The Nuremberg U-Bahn is Germany's newest metro system, having begun operation in 1972, although the Nuremberg-Fürth route (U1) uses part of the right of way of the Bavarian Ludwig Railway, Germany's first passenger railway opened in 1835. The current network of the U-Bahn is composed of three lines, serving 49 stations, and comprising 38.2 kilometres (23.7 mi) of operational route, making it the shortest of the four metro systems in Germany, behind Berlin, Hamburg and Munich.