Farris is a lake on the border of Telemark and Vestfold counties in Norway. The 20-kilometre (12 mi) long freshwater moraine-dammed lake is located mostly in Larvik Municipality in Vestfold, but the northwestern part of the lake is located in Siljan Municipality and Porsgrunn Municipality in Telemark. The large town of Larvik is located at the southern end of the lake.