Potomac (listen (help·info)) is a village in Vermilion County, Illinois, United States. It is part of the Danville, Illinois Metropolitan Statistical Area. The population was 681 at the 2000 census.
Potomac is located at 40°18′23″N 87°48′0″W / 40.30639°N 87.80000°W / 40.30639; -87.80000 (40.306351, -87.799987), about 18 miles northwest of the county seat of Danville. U.S. Route 136 passes east–west through town. The Middle Fork of the Vermilion River passes just south of the town.
According to the 2010 census, Potomac has a total area of 0.49 square miles (1.27 km), all land.
As of the census of 2000, there were 681 people, 252 households, and 191 families residing in the village. The population density was 1,408.5 people per square mile (547.8/km²). There were 277 housing units at an average density of 572.9 per square mile (222.8/km²). The racial makeup of the village was 97.21% White, 0.29% Native American, 0.29% Pacific Islander, 1.62% from other races, and 0.59% from two or more races. Hispanic or Latino of any race were 2.20% of the population.
There were 252 households out of which 36.5% had children under the age of 18 living with them, 60.7% were married couples living together, 9.1% had a female householder with no husband present, and 24.2% were non-families. 21.0% of all households were made up of individuals and 13.1% had someone living alone who was 65 years of age or older. The average household size was 2.70 and the average family size was 3.11.
In the village, the population was spread out with 28.8% under the age of 18, 6.9% from 18 to 24, 28.6% from 25 to 44, 21.6% from 45 to 64, and 14.1% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 97.4 males. For every 100 females age 18 and over, there were 96.4 males.
The median income for a household in the village was $40,221, and the median income for a family was $44,583. Males had a median income of $32,031 versus $21,417 for females. The per capita income for the village was $15,197. About 4.8% of families and 9.1% of the population were below the poverty line, including 13.2% of those under age 18 and 15.3% of those age 65 or over.