Namsen (Southern Sami: Nååmesje) is the biggest river in Nord-Trøndelag county, in the central part of Norway. The 228-kilometre (142 mi) long river flows through the municipalities of Røyrvik, Namsskogan, Grong, Overhalla, and Namsos. It traditionally has been used for floating timber down from the forests to the town of Namsos, where the sawmills were located. Today parts of the Namsen are regulated by several dams.