2020 census As of the
2020 census, Fairview Heights had a population of 16,706. The median age was 41.8 years. 19.5% of residents were under the age of 18 and 18.6% of residents were 65 years of age or older. For every 100 females there were 94.7 males, and for every 100 females age 18 and over there were 91.5 males age 18 and over. 100.0% of residents lived in urban areas, while 0.0% lived in rural areas. There were 7,197 households in Fairview Heights, of which 25.5% had children under the age of 18 living in them. Of all households, 43.0% were married-couple households, 20.6% were households with a male householder and no spouse or partner present, and 30.2% were households with a female householder and no spouse or partner present. About 31.7% of all households were made up of individuals and 11.9% had someone living alone who was 65 years of age or older. There were 7,931 housing units, of which 9.3% were vacant. The homeowner vacancy rate was 2.4% and the rental vacancy rate was 12.9%.
2000 census At the
2000 census there were 15,034 people, 6,026 households, and 4,206 families living in the city. The population density was . There were 6,310 housing units at an average density of . Of the 6,026 households 29.3% had children under the age of 18 living with them, 55.4% were married couples living together, 10.9% had a female householder with no husband present, and 30.2% were non-families. 26.6% of households were one person and 10.4% were one person aged 65 or older. The average household size was 2.48 and the average family size was 3.00. The age distribution was 23.4% under the age of 18, 7.3% from 18 to 24, 29.1% from 25 to 44, 23.8% from 45 to 64, and 16.4% 65 or older. The median age was 39 years. For every 100 females age 18 and over, there were 89.2 males. The median household income was $49,131 and the median family income was $56,161. Males had a median income of $38,287 versus $27,218 for females. The per capita income for the city was $22,614. About 4.2% of families and 5.9% of the population were below the
poverty line, including 8.7% of those under age 18 and 6.1% of those age 65 or over. ==Education==