Namsos is a town and the administrative center of Namsos Municipality in Trøndelag county, Norway. It is located on the north side of the mouth of the river Namsen, where it flows into Namsenfjorden. The village of Spillum lies across the river on the south side. The Norwegian County Road 17 runs through the town and just east of the town is Namsos Airport, Høknesøra. The town was the terminus of the Namsos Line from 1933 until its closure in 2002.