From Mon-so-ne, "Moose Tail," who was a chief at Lac Courte Oreilles in the early nineteenth century. "Little Bull Falls" became "Mosinee" on July 22, 1857, when a post office was opened there. According to one account, the postmaster,  Truman Keeler,  thought the original name was vulgar and asked a trapper named Connor for an Indian name. This person suggested that "Old Chief Mosinee" be honored, and the name was approved by the citizens. When the Post Office was moved to the west side of the river, the name was also applied to the township.  In 1889, when the village was incorporated, it retained the name of Mosinee.