2020 census

As of the census^[12] of 2020, Avon has a population of 24,847 people and 8,108 households with 2.81 persons per household. In terms of demographics, the population of Avon was 90.5% White, 4.9% African-American, 0.3% Native American, 2.4% Asian-American, 1.4% two or more races, and 2.9% Hispanic or Latino. Of the 24.847 people, 6.4% are under five-years-old, 30.3% are under 18, and 15.3% are 65 years old or older. In terms of gender, the population was recorded as 50.7% female. 96.7% of those residing in Avon who are 25 years old or older are high school graduates or higher and 53.7% of those aged 25 and older have a Bachelor's degree or a higher level of education.

2010 census

As of the census^[13] of 2010, 21,193 people, 7,584 households, and 5,750 families resided in the city. The population density was 1,018.4 inhabitants per square mile (393.2/km²). There were 8,007 housing units at a density of 384.8 per square mile (148.6/km²). The racial makeup of the city was 92.4% White, 2.3% African American, 0.1% Native American, 3.1% Asian, 0.7% from other races, and 1.4% from two or more races. Hispanics or Latinos of any race were 3.4% of the population.

Of the 7,584 households, 42.9% had children under the age of 18 living with them, 65.2% were married couples living together, 7.9% had a female householder with no husband present, 2.7% had a male householder with no wife present, and 24.2% were not families. About 20.6% of all households were made up of individuals, and 8.9% had someone living alone who was 65 years of age or older. The average household size was 2.76 and the average family size was 3.23.

The median age in the city was 38.4 years; 30.5% of residents were under the age of 18; 4.1% were between the ages of 18 and 24; 27.3% were from 25 to 44; 25.4% were from 45 to 64; and 12.6% were 65 years of age or older. The gender makeup of the city was 48.4% male and 51.6% female.

Of the city's population over the age of 25, 49.4% hold a bachelor's degree or higher.^[14]

2000 census

As of the census^[3] of 2000, 11,446 people, 4,088 households, and 3,143 families lived in the city. The population density was 548.4 people per mi² (211.8/km²). The 4,291 housing units averaged 205.6 per mi² (79.4/km²). The racial makeup of the city was 97.02% White, 0.72% African American, 0.17% Native American, 1.03% Asian, 0.24% from other races, and 0.81% from two or more races. Hispanics or Latinos of any race were 1.28% of the population.

Of 4,088 households, 37.9% had children under the age of 18 living with them, 67.7% were married couples living together, 6.4% had a female householder with no husband present, and 23.1% were not families. About 19.7% of all households were made up of individuals, and 6.8% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.15.

In the city, the population was distributed as 27.6% under the age of 18, 4.7% from 18 to 24, 31.5% from 25 to 44, 23.8% from 45 to 64, and 12.4% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 94.9 males. For every 100 females age 18 and over, there were 92.6 males.

The median income for a household in the city was $66,747, and for a family was $75,951. Males had a median income of $53,973 versus $31,660 for females. The per capita income for the city was $28,334. About 1.0% of families and 1.9% of the population were below the poverty line, including 0.9% of those under age 18 and 2.5% of those age 65 or over.