Tomahawk Lake is a lake in Oneida County, Wisconsin, United States. The lake covers an area of 3,392 acres (1,373 ha) and has a maximum depth of 84 feet (26 m). The community of Lake Tomahawk is located on the eastern edge of the lake. Tomahawk Lake was so named from the fact its outline resembles a tomahawk.Tomahawk Lake is the source of the Tomahawk River.