Fairbury is a city in Livingston County, Illinois, United States. The population was 3,968 at the 2000 census.
Fairbury is located at 40°44′46″N 88°30′51″W / 40.746103°N 88.514092°W / 40.746103; -88.514092.
According to the 2010 census, Fairbury has a total area of 1.8 square miles (4.66 km), all land.
As of the census of 2000, there were 3,968 people, 1,544 households, and 1,053 families residing in the city. The population density was 3,060.1 people per square mile (1,178.5/km²). There were 1,623 housing units at an average density of 1,251.7 per square mile (482.0/km²). The racial makeup of the city was 96.80% White, 0.40% African American, 0.05% Native American, 0.45% Asian, 1.66% from other races, and 0.63% from two or more races. Hispanic or Latino of any race were 2.60% of the population.
There were 1,544 households out of which 34.3% had children under the age of 18 living with them, 56.5% were married couples living together, 8.4% had a female householder with no husband present, and 31.8% were non-families. 28.2% of all households were made up of individuals and 15.2% had someone living alone who was 65 years of age or older. The average household size was 2.48 and the average family size was 3.05.
In the city, the population was spread out with 27.0% under the age of 18, 7.5% from 18 to 24, 25.5% from 25 to 44, 19.0% from 45 to 64, and 21.0% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 90.2 males. For every 100 females age 18 and over, there were 85.2 males.
The median income for a household in the city was $41,298, and the median income for a family was $51,117. Males had a median income of $33,507 versus $24,188 for females. The per capita income for the city was $19,145. About 3.3% of families and 4.9% of the population were below the poverty line, including 3.5% of those under age 18 and 4.3% of those age 65 or over.