Dunseith was platted in 1882. The town is named for Jeannette Dunseith Eaton, who was the mother of the town's founder William Eaton. A post office has been in operation in Dunseith since 1884. The city was incorporated in 1908.
Dùnsìth is a Gaelic word meaning "City of Peace," from dùn (English: fortress) and sìth (English: peace). It is fitting that Dunseith is the Gateway to the International Peace Gardens located just 14 miles North.