Potomac is a census-designated place (CDP) in Montgomery County, Maryland, United States, named for the nearby Potomac River. The population was 44,822 at the 2000 census. The Potomac area is known for its very affluent and highly-educated residents. CNNMoney. com placed Potomac seventh on its list of top-earning American towns for 2008, one place ahead of neighboring McLean, Virginia. Potomac is also the seventh top-educated American small town according to Forbes. Many Potomac residents work in Washington, D.C..