Mount Prospect is a village in Elk Grove Village and Wheeling Townships in Cook County, Illinois, about 20 miles (32 km) northwest of downtown Chicago, and approximately 4 miles north of O'Hare International Airport. As of the 2020 census, the village had a total population of 56,852

As of the 2020 census there were 56,852 people, 20,855 households, and 15,043 families residing in the village. The population density was 5,285.12 inhabitants per square mile (2,040.60/km2). There were 22,835 housing units at an average density of 2,122.80 per square mile (819.62/km2). The racial makeup of the village was 66.37% White, 2.69% African American, 0.68% Native American, 14.49% Asian, 0.05% Pacific Islander, 8.01% from other races, and 7.70% from two or more races. Hispanic or Latino of any race were 16.16% of the population.

There were 20,855 households, out of which 32.7% had children under the age of 18 living with them, 60.11% were married couples living together, 8.05% had a female householder with no husband present, and 27.87% were non-families. 23.61% of all households were made up of individuals, and 11.86% had someone living alone who was 65 years of age or older. The average household size was 3.09 and the average family size was 2.59.

The village's age distribution consisted of 22.9% under the age of 18, 5.3% from 18 to 24, 27.2% from 25 to 44, 26.5% from 45 to 64, and 18.1% who were 65 years of age or older. The median age was 40.8 years. For every 100 females, there were 98.7 males. For every 100 females age 18 and over, there were 94.4 males.

The median income for a household in the village was $84,353, and the median income for a family was $103,946. Males had a median income of $57,695 versus $41,193 for females. The per capita income for the village was $40,452. About 3.7% of families and 5.8% of the population were below the poverty line, including 4.9% of those under age 18 and 8.4% of those age 65 or over.