Similarly to Berlin but unlike Hanover, the S-Bahn is an important part of public transport within the city due to its dense schedule and good coverage of the metropolitan region.

Unlike both Berlin and Hanover, the S-Bahn is of little importance for regional traffic since the network lies mostly within the city, though in 2007 the southwestern S3 line was extended about 32 km (20 mi) into the state of Lower Saxony (the Neugraben - Stade portion, which included seven new stations).

It ran alongside the Lübeck–Hamburg line of the Lübeck-Büchen Railway Company as far as Hasselbrook and then on its own tracks as far as the new Ohlsdorf cemetery.

A railway line constructed and operated by a local company in 1914 and taken over by the district of Stormarn after bankruptcy, led from Ohlsdorf to Poppenbüttel in Prussia, with the goal of connecting neighbouring settlements along the Alster river.

In order to allow improved acceleration, the S-Bahn uses 1200 volts: as a consequence, Berlin and Hamburg rolling stock are not compatible with each other.

The basic DC train unit consisted of three four-axle carriages, each with four sliding double doors per side.

The DC S-Bahn was extended along the single-track suburban line from Blankenese to Sülldorf in 1950 and to Wedel in 1954.

A section of the mainline railway between Hamburg and Berlin, which, due to the division of Germany, had very little traffic, between Haupbahnhof and Bergedorf was added to the network in 1959 by the addition of the third rail.

In 1962 a connecting curve was constructed from the Verbindungsbahn at Holstenstraße to the Altona-Kaltenkirchen railway, whose terminus was relocated to Langenfelde.

In 1965, the German Railway, along with two local transport companies, founded the Hamburger Verkehrsverbund, a common tariff system for U-Bahn and bus lines.

The first section was opened in 1975 between Hauptbahnhof and Landungsbrücken, the extension to Altona in 1979 and was completed in 1981 with the connection above ground to Diebsteich.

[7] 1983 saw the opening of the line via Wilhelmsburg to Harburg Rathaus, a long stretch of which runs along the existing mainline.

The section to Reinbek was reopened in 1997; completion to Aumühle was delayed until 2002 due to court challenges from local residents.

The S-Bahn is represented in German cities with a logo consisting of a white "S" in a green circle.

The company currently employs approximately 1200 personnel in the driving, maintenance, train departure and resource management[8] divisions.

(Stations with names bold in the following table offer a turning option) Plans, currently shelved, would have the S-Bahn network dramatically increased.

The initiative is currently basing their arguments on a feasibility study which was ordered by S-Bahn Hamburg GmbH in the year 2002, and in principle dusted off the plans from the 1960s.

According to the study, the extension involves upgrading the line to proper S-Bahn standards, served by EMUs and the addition of extra stations.

In Schleswig-Holstein, the establishment of an additional stopping point near the existing U-Bahn station Ahrensburg West is planned.

The platforms of the existing stations will be adjusted in height and length for S-Bahn operations; In Tonndorf , Ahrensburg , Kupfermühle and Bad Oldesloe the existing systems can be raised to the height of 96 cm customary in the S-Bahn network, in Rahlstedt , Gartenholz and Bargteheide this requires a completely new building.

In the first step, all platforms will be built with a length of at least 140 m, a later expansion to serve the route with long trains was taken into account in the planning.

In June 2022, The S-Bahn Hamburg announced a new network system which will be in effect starting December 2023 on the nationwide schedule switch.

[12] The S1 travels from its original line track of Airport/Poppenbüttel to Blankenese/Wedel and vice versa with the addition of Ottensen S-Bahn Station in between Altona and Bahrenfeld.

In light of the track shorting for the S3, the S5 is introduced and runs between Elbgaustraße and Stade vice versa via the Verbindungsbahn, without stop in Altona.

These are identical to the type 474 units but with a pantograph on the central carriage to collect 15 kV alternate current from overhead lines.

The implementation of a consistent corporate design led to type 472 trains being updated with the new colour scheme.

At the interchange stations Hauptbahnhof and Altona there are two island platforms, one for trains to the city centre and one for the other direction.

There is an all-night service within the Hamburg section on the nights before Saturdays, Sundays, and public holidays in Germany.

Multiple lines running on the same tracks, mainly through the city centre but also along the routes served by the S2/S21 and the S3/S31, have shorter intervals.