Vergennes is a village in Jackson County, Illinois, United States. The population was 235 at the 2020 census.

On February 28, 2017, a strong tornado, possibly the same as the one that struck Perryville, Missouri, narrowly missed the center of town, though no fatalities occurred.

Vergennes is located in northern Jackson County at 37°54′11″N 89°20′24″W / 37.90306°N 89.34000°W / 37.90306; -89.34000 (37.903152, -89.340111). Illinois Route 13 runs through the east side of the village, leading north 13 miles (21 km) to Pinckneyville and south 10 miles (16 km) to Murphysboro, the Jackson county seat.

According to the 2021 census gazetteer files, Vergennes has a total area of 0.35 square miles (0.91 km), of which 0.35 square miles (0.91 km) (or 99.44%) is land and 0.00 square miles (0.00 km) (or 0.56%) is water.

Historical population

Census	Pop.	Note	%±
1890	275		—
1900	416		51.3%
1910	342		−17.8%
1920	305		−10.8%
1930	309		1.3%
1940	324		4.9%
1950	312		−3.7%
1960	298		−4.5%
1970	323		8.4%
1980	360		11.5%
1990	314		−12.8%
2000	491		56.4%
2010	298		−39.3%
2020	235		−21.1%
U.S. Decennial Census

As of the 2020 census there were 235 people, 98 households, and 72 families residing in the village. The population density was 663.84 inhabitants per square mile (256.31/km). There were 113 housing units at an average density of 319.21 per square mile (123.25/km). The racial makeup of the village was 93.19% White, 0.43% African American, 0.43% Native American, 0.00% Asian, 0.00% Pacific Islander, 0.00% from other races, and 5.96% from two or more races. Hispanic or Latino of any race were 2.13% of the population.

There were 98 households, out of which 33.7% had children under the age of 18 living with them, 50.00% were married couples living together, 17.35% had a female householder with no husband present, and 26.53% were non-families. 23.47% of all households were made up of individuals, and 18.37% had someone living alone who was 65 years of age or older. The average household size was 2.86 and the average family size was 2.43.

The village's age distribution consisted of 26.1% under the age of 18, 8.0% from 18 to 24, 24.8% from 25 to 44, 21.5% from 45 to 64, and 19.7% who were 65 years of age or older. The median age was 37.2 years. For every 100 females, there were 116.4 males. For every 100 females age 18 and over, there were 85.3 males.

The median income for a household in the village was $41,875, and the median income for a family was $51,667. Males had a median income of $33,500 versus $22,188 for females. The per capita income for the village was $21,311. About 12.5% of families and 9.7% of the population were below the poverty line, including 13.1% of those under age 18 and 8.5% of those age 65 or over.