Rengen is a lake on the border between Sweden and Norway. The 21.49-square-kilometre (8.30 sq mi) lake covers 15.72 square kilometres (6.07 sq mi) in Norway and 5.77 square kilometres (2.23 sq mi) in Sweden. The Norwegian part is located in the municipality of Lierne in Nord-Trøndelag county, and the Swedish part is located in the municipality of Krokom in Jämtland County.