T-Centralen (Swedish for "The T-Central"; T being an abbreviation for "tunnelbana", the Swedish word for "underground" or "subway") is a metro station that forms the heart of the Stockholm metro system, in the sense that it is the only station where all three of the system's lines meet. That, its central location, and its connections with other modes of transport make it the busiest station in the system. The station is located in the Norrmalm borough of Stockholm, between Sergels torg (Sergel's Square) and the street of Vasagatan.

On a winter day in 2018, some 340,000 passengers (174,550 boarding and 166,850 alighting) travelled to or from the metro station. It is connected by a pedestrian underpass to the neighbouring Stockholm Central Station across Vasagatan (for national and regional trains) and to the Cityterminalen long-distance bus terminal, making it easy to continue a journey started by metro train.

When opened on 24 November 1957 the name of the station was "Centralen" ("The Central"), but it was renamed on 27 January 1958, as the metro station often was mistaken for the central railway station to which it is connected, but with some distance. During construction, it was intended to be called Klara, but that name was abandoned before opening. T-Centralen has two separate sets of platforms, connected by a long moving walkway on a mezzanine level. The station was open as part of the section connecting Slussen and Hötorget thereby west and east sections of the green line. On 5 April 1964, T-Centralen became the north terminus of the first stretch of the Red line running to Fruängen. On 16 May 1965, the Red line was extended north to Östermalmstorg. On 31 August 1975, the first stretch of the Blue Line to Hjulsta was opened. The trains were running via Hallonbergen and Rinkeby. On 30 October 1977, a one-station extension of the Blue line east to Kungsträdgården was opened.

The Stockholm City commuter rail station is located below the metro station, with direct escalators to the metro platforms. It opened on 10 July 2017 as part of the Stockholm City Line. Since 2018, T-Centralen has been the western terminus of the Spårväg City tramway.