Seljord is a municipality in Telemark county, Norway. It is located in the traditional districts of Upper Telemark and Vest-Telemark. The administrative centre of the municipality is the village of Seljord. Other villages in the municipality include Flatdal and Åmotsdal.

Telemark is a county and a current electoral district in Norway. Telemark borders the counties of Vestfold, Buskerud, Vestland, Rogaland and Agder. In 2020, Telemark merged with the county of Vestfold to form the county of Vestfold og Telemark. On 1 January 2024, the county of Telemark was re-established after Vestfold og Telemark was divided again.