Namdalseid is village and a municipality in Nord-Trøndelag county, Norway. It is part of the Namdalen region. The administrative centre of the municipality is the village of Namdalseid. Other villages and farm areas include Sjøåsen, Statland, Tøttdalen, and Sverkmoen.
The village of Namdalseid lies along Norwegian County Road 17 between Sjøåsen and Vellamelen (in Steinkjer). The 0.34-square-kilometre (84-acre) village has a population (2011) of 327. The population density of the village is 962 inhabitants per square kilometre (2,490 /sq mi).
Namdalseid was established as a municipality on 1 January 1838 (see formannskapsdistrikt), but is was merged into the neighboring municipality of Beitstad on 1 January 1846. On 1 January 1904, the Namdalseid district (population: 1,368) was separated from Beitstad to form a municipality of its own (once again). On 1 January 1964, the parts of the neighboring municipality of Otterøy that were located south of the Namsenfjorden (population: 571) were transferred to Namdalseid.