The Zurich S-Bahn (German: S-Bahn Zürich) system is a network of rail lines that has been incrementally expanded to cover the ZVV area, which comprises the entire canton of Zurich and portions of neighbouring cantons (Aargau, Glarus, Schaffhausen, Schwyz, St. Gallen, Thurgau and Zug), with a few lines extending into or crossing the territory of southern Germany. The network is one of many commuter rail operations in German speaking countries to be described as an S-Bahn. The lines connect with services of Aargau S-Bahn to the West, Basel S-Bahn (only in Waldshut) and Schaffhausen S-Bahn to the North, St. Gallen S-Bahn to the East, and Lucerne S-Bahn/Zug Stadtbahn to the South, as well as with InterCity, InterRegio and RegioExpress services at major junction stations.
The entire ZVV S-Bahn network went into operation in May 1990, although many of the lines were already in operation.