Lake Monticello is a census-designated place (CDP) in Fluvanna County, Virginia, United States. The population was 9,920 at the 2010 census, an increase of over 44% from 2000. The community is centered on a lake of the same name, which is formed by a dam on a short tributary of the nearby Rivanna River. Lake Monticello is part of the Charlottesville Metropolitan Statistical Area. It's essentially a bedroom community of Charlottesville, and to a smaller extent Richmond. It also has a sizable retirement age population.GeographyLake Monticello is located at .According to the United States Census Bureau, the CDP has a total area of 9.4 square miles , of which 8.8 square miles is land and 0.6 square mile is water.DemographicsAs of the census of 2000, there were 6,852 people, 2,754 households, and 2,194 families residing in the CDP. The population density was 780.9 people per square mile (301.7/km²). There were 2,950 housing units at an average density of 336.2/sq mi (129.9/km²). The racial makeup of the CDP was 94.06% White, 3.50% African American, 0.16% Native American, 0.51% Asian, 0.03% Pacific Islander, 0.28% from other races, and 1.46% from two or more races. Hispanic or Latino of any race were 1.49% of the population.