The Oslo Metro is the rapid transit system of Oslo, Norway, operated by Sporveien T-banen on contract from the transit authority Ruter. The network consists of five lines that all run through the city centre, with a total length of 85 kilometres (53 mi), serving 101 stations of which 17 are underground or indoors. In addition to serving 14 out of the 15 boroughs of Oslo, two lines run to Kolsås and Østerås, in the neighbouring municipality of Bærum. In 2016, the system had an annual ridership of 118 million.

Nationaltheatret is an underground metro station and tram stop serving Vika and the city center of Oslo, Norway. It is located on the Common Tunnel of the Oslo Metro and on the Briskeby Line of the Oslo Tramway. Also located at the same place is Nationaltheatret Station of the Drammen Line. The station is served by all five lines of the metro, and lines 11 and 13 of the tramway. In addition, several bus services call at the station. It is named for the National Theatre located nearby.