Nationaltheatret is an underground metro station and tram stop serving Vika and the city center of Oslo, Norway.

Nationaltheatret was the first underground station in the Nordic countries; construction of a 1.6-kilometre (1.0 mi) tunnel from Majorstuen to the city center started in 1912, but was not finished until 1928.

Nationaltheatret is Norway's first underground mainline railway station, located within the Oslo Tunnel on the Drammen Line.

The area features escalators and elevators to the platforms, staffed ticket sales, lockers, kiosks and cafés.

[5] It is served by Ruter bus lines, 30 Nydalen-Bygdøy, 31 (Grorud T)-Tonsenhagen—Fornebu-(Snarøya), 32 Kværnerbyen-Voksen skog, 33 Ellingsrudåsen T-Filipstad, and more.

Eastwards, these continue past Oslo S and serve the southern part of the Dovre Line until Lillehammer (RE10).

Either sign trafficking rights with Kristiania Elektriske Sporvei to use their tracks on the Briskeby Line to reach the city center.

On 9 June 1911, the city council voted that they would accept the tunnel if the terminus was moved to the intersection of Karl Johans gate and Ruseløkkveien, but this was rejected by the company.

Aker Municipal Council voted on 27 May 1909 that they were in favor of the tunnel, and on 9 June 1911 the proposal was passed by the Parliament of Norway.

[13] In 1915, a competition for a plan for the city's tramway light rails was launched, although it took two years for the invitation to be issued.

In July 1918, the winner was announced, and in September 1919 a committee made a suggestion for how to expand the light rail network.

[15] Following a competition for the design of a new light rail network in the city, which was concluded in 1919, the municipality to again consider the terminus of the tunnel.

The executive committee supported terminating the tunnel at Eidsvolls plass, but this was rejected by the city council on 13 July 1920.

In September 1921, the committee proposed creating a temporary terminus, following Holmenkolbanen's route, in the square behind the National Theatre.

[15] In June 1923, the executive committee voted to allow a temporary terminus at Nationaltheatret, while Holmenkolbanen were obliged to continue the line onwards to Studenterlunden.

[16] Past Slottsparken the original track had been built with increased depth to allow a potential extension of the Drammen Line of the Norwegian State Railways to run above the light rail tunnel.

[24] Led by Axel Grenholm,[25] the committee recommended building a branch from the Drammen Line as a tunnel under the city center, allowing all trains would terminate at Oslo Ø.

[24] The proposal was presented to the Parliament of Norway on 4 November 1961, along with several other matters related to rail transport investments.

[28] Simultaneously, Oslo Sporveier worked with possibilities to connect their eastern and western networks, and get both into the city core.

However, the initial plans involved creating a station close to Nationaltheatret, named for Slottsparken, which would serve as the transfer point between the two systems.

[30] The initial plans were met with criticism, following media's discovery that the main planners had not consulted several hired specialists, and that alternatives to the preferred route had not been made.

[34] In 1978, the city planner discarded the proposal from Oslo Sporveier to build a new station at Slottsparken, and instead decided that Stortinget would become the interchange between the two systems.

The line, including the Common Tunnel and Nationaltheatret, were upgraded to metro standard by replacing the overhead wire with a third-rail power supply and installing automatic train protection.

[41] From 1998, the Airport Express Train would start operating, and more capacity would be needed, both at Nationaltheatret and through the Oslo Tunnel.