Rjukan is a town situated in Tinn Municipality within the Telemark county of Norway. It serves as the administrative center for the municipality and was officially declared a town by the municipal council in 1996.
Geographically, the town is positioned in the Vestfjorddalen valley, nestled between the lakes Møsvatn and Tinnsjå. It is located approximately ten kilometres west of the village of Miland and about 20 kilometres northwest of the village of Tuddal.