Allerton is a village in Sidell Township, Vermilion County, Illinois, United States. A small portion of the village extends into Champaign County. The population was 291 at the 2010 census.
Allerton is located near the southwestern corner of Vermilion County at 39°54′46″N 87°56′8″W / 39.91278°N 87.93556°W / 39.91278; -87.93556 (39.912859, -87.935636). The village extends west into Champaign County in two places. Champaign-Urbana is about 30 miles (48 km) to the northwest, and Danville is the same distance to the northeast.
According to the 2010 census, Allerton has a total area of 0.68 square miles (1.76 km), all land. Allerton is located on the county line, and a small portion of is located in Champaign County, Illinois.
As of the census of 2000, there were 293 people, 112 households, and 89 families residing in the village. The population density was 454.4 people per square mile (176.8/km²). There were 122 housing units at an average density of 189.2 per square mile (73.6/km²). The racial makeup of the village was 97.61% White, 0.68% Native American, and 1.71% from two or more races. Hispanic or Latino of any race were 2.39% of the population.
There were 112 households out of which 38.4% had children under the age of 18 living with them, 64.3% were married couples living together, 10.7% had a female householder with no husband present, and 20.5% were non-families. 18.8% of all households were made up of individuals and 13.4% had someone living alone who was 65 years of age or older. The average household size was 2.62 and the average family size was 2.93.
In the village, the population was spread out with 28.3% under the age of 18, 7.8% from 18 to 24, 27.6% from 25 to 44, 22.9% from 45 to 64, and 13.3% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 98.0 males. For every 100 females age 18 and over, there were 101.9 males.
The median income for a household in the village was $42,250, and the median income for a family was $51,964. Males had a median income of $38,611 versus $28,750 for females. The per capita income for the village was $17,512. None of the families and 4.5% of the population were living below the poverty line, including no under eighteens and 8.6% of those over 64.