The Røa Line is a rapid transit line of the Oslo Metro, Norway, which runs from Majorstuen in Oslo to Østerås in Bærum. It serves neighborhoods such as Smestad, Hovseter, Huseby and Røa in northwestern Oslo, and Grini, Øvrevoll and Østerås in northeastern Bærum. The line is served by Line 2 of the metro, which connects to the city center via the Common Tunnel and onwards along the Furuset Line. The lowest part of the Røa Line, consisting of two stations, is shared with the Kolsås Line, and thus also served by Line 2 of the metro. The Røa Line is owned by Kollektivtransportproduksjon, and operated by Oslo T-banedrift on contract with the public transport agency Ruter.

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.