Trams make an important contribution to public transport in the city of Zurich in Switzerland. The tram network serves most city neighbourhoods, and is the backbone of public transport within the city, albeit supplemented by the inner sections of the Zurich S-Bahn, along with urban trolleybus and bus lines, as well as two funicular railways, one rack railway and passenger boat lines on the river and on the lake. The trams and other city transport modes operate within a fare regime provided by the cantonal public transport authority Zürcher Verkehrsverbund (ZVV), which also covers regional rail and bus services.

The city's trams are operated by the Verkehrsbetriebe Zürich (VBZ), which also manages the tramway infrastructure within the city, but the city's tram tracks are also used by three other operations. The Glattalbahn tram services to the Glattal area to the north of the city interwork with the city tram services and are also operated by the VBZ, although in this case it does so as a sub-contractor to the Verkehrsbetriebe Glattal (VBG). Trains of the independent Forchbahn (FB) light railway also use the city's tram lines to reach their city centre terminus. In 2022, the Limmattalbahn began using part of line 20.

Trams have been a consistent part of Zurich's streetscape since the 1880s, when the first horse tram ran. Electrified from the 1890s, they have seen off challenges including proposals to replace them by trolleybuses and by a metro or U-Bahn. With a relatively static city network from the 1930s to the late 1970s, the city's trams have been expanding again since then. Recent expansions have taken the network into the suburbs beyond the city boundary, covering areas it retreated from in the first part of the 20th century. Further extensions have been approved, both to the city tram network itself, and by the introduction of a new light rail system in the Limmat Valley that will interwork with the city trams.

Various projects to introduce trams to Zurich were proposed from the 1860s onwards. It was not until 1882, however, that the first tram operated in the city. These initial trams were operated by the Zürcher Strassenbahn Gesellschaft [de] (ZStG), a private company, and were of standard gauge (1,435 mm or 4 ft 8+1⁄2 in gauge) and horse-drawn.

By 1888 the first electric tramway in Switzerland (the Vevey–Montreux–Chillon tramway) had opened, and, in 1894, another private company, the Elektrische Strassenbahn Zürich [de] (EStZ), started operating metre gauge (3 ft 3+3⁄8 in gauge) electric trams in Zurich. The EStZ only survived for two years before it was taken over by the City of Zurich, who renamed it the Städtische Strassenbahn Zürich (StStZ). The following year, the horse trams of the ZStG were acquired.

Further tramway companies were founded, some operating entirely within the city, some connecting the city with its nearer suburbs, and some running in rural areas entirely beyond the city, but still linked by connections with other lines to the city. Like the EStZ, all these lines were electrified and were built to the metre gauge. The StStZ gradually took over those companies that had significant city operations, usually closing any cross-boundary lines, whilst leaving those lines entirely beyond the city to their own devices.

By the mid-1930s, the StStZ had acquired all the companies that had operated tramways within the city boundaries, with the single exception of the Dolderbahn, which had closed its short tramway in 1930. The standard gauge horse tram lines had all been converted to metre gauge and electrified. The StStZ had also built many tram extensions, resulting in a dense network of tramlines serving most city neighbourhoods.

However, in 1927, the StStZ had introduced its first motor bus line, and this was to be followed in 1939 by the first of the city's trolleybus lines. Initially these modes complemented the trams, but at various times they have threatened to replace parts of the tram system, and sometimes succeeded in doing so.