23rd largest of 30
Among Illinois’s 30 cities of 50,000+ residents, Mount Prospect ranks 23rd by population (55,395, July 2025).

Mount Prospect has 55,395 residents (−2.6% since 2020), a median household income of $101,720 and 29.6% foreign-born residents.
Photo: bogdanstepniak · CC BY 3.0 · Wikimedia CommonsMount Prospect is a city in Illinois. The Census Bureau estimates 55,395 residents in July 2025, compared with 56,852 counted in the 2020 Census. With 11 square miles of land, it had 5,303 people per square mile in 2020. These figures describe the city itself, not its county or metropolitan area.
Pick an indicator to see its long-run evolution.
Census Bureau Population Estimates Program (Vintage 2020 for 2010–2019, Vintage 2025 from 2020).
| Indicator | Value | Year and source |
|---|---|---|
| Population estimate, 2025 | 55,395 | Census Bureau, Vintage 2025 |
| Population estimates base, April 2020 | 56,858 | Census Bureau |
| Population, 2020 Census | 56,852 | Decennial Census |
| Population, 2010 Census | 54,167 | Decennial Census |
| Population, 2000 Census | 56,265 | Decennial Census |
| Land area | 10.7 mi² | Census Gazetteer 2024 |
| Median age | 41.1 years | ACS 2020–2024 |
| Per capita income | $48,661 | ACS 2020–2024 |
| Owner-occupied housing | 68.7% | ACS 2020–2024 |
| Unemployment rate | 3.8% | Civilian labor force · ACS 2020–2024 |
| Veterans | 1,726 | Civilians 18+ · ACS 2020–2024 |
Comparable indicators for the city, California and the United States.
| Indicator | City | California | U.S. | Reference |
|---|---|---|---|---|
| Median household income | $101,720 | $83,390 | $80,734 | ACS 2020–2024 |
| Median home value | $397,400 | $263,300 | $332,700 | ACS 2020–2024 |
| Median gross rent | $1,502 /month | $1,274 /month | $1,413 /month | ACS 2020–2024 |
| Poverty rate | 6.6% | 11.8% | 12.5% | ACS 2020–2024 |
| Bachelor’s degree or higher | 48.6% | 37.8% | 35.7% | ACS 2020–2024 |
| Foreign-born residents | 29.6% | 14.7% | 14.1% | ACS 2020–2024 |
| Owner-occupied housing | 68.7% | 67.1% | 65.2% | ACS 2020–2024 |
| Median age | 41.1 years | 39.0 years | 38.9 years | ACS 2020–2024 |
Among Illinois’s 30 cities of 50,000+ residents, Mount Prospect ranks 23rd by population (55,395, July 2025).
The city lost 1,463 residents (−2.6%) from April 2020 to July 2025, 22nd for growth among the state’s 30 large cities.
The census counted 56,265 residents in 2000 and 56,852 in 2020, a +1.0% change.
Median household income is $101,720, +22.0% versus Illinois ($83,390); 9th of 30 large cities.
The median owner-occupied home is worth $397,400, 7th highest of the state’s 30 large cities.