Lake Monticello, a private gated community, is a census-designated place (CDP) in Fluvanna County, Virginia, United States. The population was 10,126 at the 2020 census. 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. Lake Monticello was developed in the 1960s as a summer vacation home community but quickly evolved into a bedroom community of Charlottesville, and to a smaller extent of Richmond. It also has a sizable retirement age population.

Fluvanna County is a county located in the Piedmont region of the Commonwealth of Virginia, United States. As of the 2020 census, the population was 27,249. Its county seat is Palmyra, while the most populous community is the census designated place of Lake Monticello.