Ulen is a city in Clay County, Minnesota, United States, along the South Branch of the Wild Rice River. The population was 476 at the 2020 census. Near this small community, what may be an authentic Viking sword known as the Ulen sword was found in a field by Hans O. Hansen in 1911. The sword is currently on display in the Ulen Museum. Ulen and the area surrounding is mostly inhabited by later generation Norwegian-Americans.