Namdalen

thumb|right|Bangsund near Namsos thumb|right|Heia in Grong Municipality; the E6 road follows Namdalen for about 100 km

Namdalen () is a traditional district in the central part of Norway, consisting of the municipalities of Namsos, Grong, Overhalla, Røyrvik, Nærøysund, Høylandet, Flatanger, Lierne, Leka, and Namsskogan, all in Trøndelag county. The district has three towns: Namsos, Rørvik and Kolvereid. The whole district covers about and has about 35,000 residents (2009).