|First service||11 June 2019|
|Current operator(s)||Swiss Federal Railways|
|Distance travelled||28.9 kilometres (18.0 mi)|
|Average journey time||33 minutes|
|Service frequency||Three round-trips on weekdays|
|Line(s) used||Lake Zürich right-bank railway line|
The S20 is a railway service of the Zürich S-Bahn that provides rush-hour service between Zürich Hardbrücke and Uerikon, in the Swiss canton of Zürich. Swiss Federal Railways operates the service.
The S20 was introduced on 11 June 2019, with the initial southeastern terminus at Stäfa. It was extended from Stäfa to Uerikon with the December 2021 timetable change.
As of the December 2021 timetable change,[update] there are four departures in the morning from Uerikon and three in the late afternoon/early evening from Zürich Hardbrücke. The service does not operate on weekends. Most services are operated by SBB-CFF-FFS Re 420 locomotives pulling coaches.