The Town of Lakeside is a Statutory Town in Jefferson County, Colorado, United States. The town population was 16 at the 2020 United States Census, making Lakeside the least populous municipality in the State of Colorado. Lakeside is immediately west of the City and County of Denver, the most populous municipality in the state. The Denver Post Office serves Lakeside. The town's namesake lake is Lake Rhoda, which covers 20% of its total area.