Eastern Norway is the geographical region of the south-eastern part of Norway. It consists of the counties Oslo, Akershus, Vestfold, Østfold, Buskerud, Telemark, and Innlandet.

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.