Downsville is an unincorporated census-designated place in the town of Dunn, located within Dunn County, Wisconsin, United States, where Highway 25 crosses the Red Cedar River. As of the 2020 census, its population was 188, down from 146 at the 2010 census. The community was founded in 1855. Around that time, Ebenezer Thompson tried to dam the Red Cedar, but his half-built dam was destroyed by a flood. In 1857 Captain Downs tried again and succeeded in building a dam which powered a sawmill. The village was platted in 1859, and named for Downs. He sold the mill to Knapp, Stout & Co., who expanded it and added planing and shingle mills which employed about 100 men by 1891. By that year the town also had a steam feed mill and a stop on the Menomonie branch of the Chicago, Milwaukee & St Paul Railway.