Ruter AS is the public transport authority for Oslo and Akershus counties in Norway. Formally a limited company – 60% of its shares are owned by the Oslo county municipality and 40% by that of Viken – it is responsible for the administration, funding, and marketing of public transport in the two counties, including buses, the Oslo Metro, Oslo Trams, and ferry services. Ruter also holds agreements with Entur concerning the regulation of fares on local and regional train services operated within the two counties.

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.