Selbusjø or Selbusjøen is the 17th largest lake in Norway. It is located in Sør-Trøndelag county, primarily in the municipality of Selbu, although the western end of it lies in Klæbu. The 58.26-square-kilometre (22.49 sq mi) lake is the largest lake in Sør-Trøndelag county. Selbusjø is part of the Nea-Nidelv watershed, with the Nea River flowing into it on the eastern end and the Nidelva River flowing out the western end. The villages of Selbustrand, Fossan, Tømra, Trøa, Innbygda, Mebonden, Vikvarvet, and Sjøbygda lie around the lake.