The Numedal Line (Norwegian: Numedalsbanen) is a 92.8-kilometer (57.7 mi) long railway line that runs up the Numedal valley between Kongsberg and Rødberg in Buskerud, Norway. Built and operated by the Norwegian State Railways, the non-electrified, standard gauge line passes through the municipalities of Kongsberg, Flesberg, Rollag and Nore og Uvdal. It is now owned by the Norwegian National Rail Administration.
The first plans for a line through Numedal were launched after the Sørland Line reached in Kongsberg in 1871. After it was decided that the Bergen Line would instead follow Hallingdal, the Numedal plans lay dead until it was decided that a railway was necessary to build two hydroelectric power stations near Rødberg. The plans were passed in 1918, the first trains started running in 1924 and the line was officially opened in 1927. At first all services were provided with steam locomotives, but from the 1930s diesel multiple units were used for passenger trains. The line was frequented with classes Cmd 16, 86, 87 and 91. The last regular train ran in 1988; since, there has been sporadic freight service and some heritage trains running from Kongsberg to Rollag. Draisine rental is available on the section from Veggli to Rødberg.
Numedal is a valley and a traditional district in Eastern Norway located within the county of Buskerud. It traditionally includes the municipalities Flesberg, Nore og Uvdal and Flesberg, but administratively, it includes Kongsberg, as well.
Numedal is the southernmost valley of the major valleys in Eastern Norway. Numedal is a largely a U-shaped valley. Most of the area is mountainous, especially west of the main valley, with steep valley sides. Running north–south, it extends between Flesberg in the south to Rødberg in the north, passing through the municipalities of Flesberg, Rollag and Nore og Uvdal. The Numedalslågen, the third-longest river in Norway, flows through the valley before discharging into Oslofjord at Larvik. National Road 40 runs from Larvik. National Road 7 crosses Hardangervidda to Geilo. Numedal Line Railway (Numedalsbanen) was opened in 1927 and stopped operations in 1988. The former railroad track from Veggli to Rødberg is now used principally for cycling. Agriculture and forestry are important industries in the valley along with hydropower generation, as well as growing tourist traffic.