Illinois projected population growth from 2025 through 2035

Illinois, the Prairie State, is known for its vibrant cities, diverse culture, and rich history. From the iconic skyline of Chicago to the rolling farmland of central Illinois, the state offers a blend of urban sophistication and rural charm. With a diverse economy supported by industries such as finance, manufacturing, and healthcare, Illinois continues to attract individuals seeking career opportunities and cultural amenities.

Picture from a ciy in Illinois U.S.

Illinois forecasted population

Aterio data team has developed an AI enhanced model that helps organizations understand the forecasted growth of population in Illinois for years 2025 through 2035.

Population Growth Rate (Year over Year)

12,300,00012,400,00012,500,00012,600,00012,700,00012,800,00012,900,000-1.00%-0.50%0.00%0.50%1.00%2020202120222023202420252026202720282029203020312032203320342035

2020

Population

12,821,814

Growth

0.00%

2021

Population

12,700,641

Growth

-0.95%

2022

Population

12,621,821

Growth

-0.62%

2023

Population

12,642,259

Growth

0.16%

2024

Population

12,710,158

Growth

0.54%

2025

Population

12,695,728

Growth

-0.11%

2026

Population

12,661,926

Growth

-0.27%

2027

Population

12,631,396

Growth

-0.24%

2028

Population

12,604,743

Growth

-0.21%

2029

Population

12,579,970

Growth

-0.20%

2030

Population

12,556,457

Growth

-0.19%

2031

Population

12,512,327

Growth

-0.35%

2032

Population

12,469,454

Growth

-0.34%

2033

Population

12,427,659

Growth

-0.34%

2034

Population

12,387,985

Growth

-0.32%

2035

Population

12,349,857

Growth

-0.31%

Last update at Tue Sep 29 2026

Zip code level csv report on population forecast and economic development in Illinois

Our team has created a comprehensive report on population forecast and economic development by zip code using our proprietary AI models.

Top 10 most populated cities in Illinois

Our model provides a detailed 2025 through 2035 forecasted population growth for every city and zip code in Illinois.

City

2020 census

2025 population

2030 population

2035 population

Open
Chicago2,748,3312,725,7272,692,7392,648,884View city insights, Chicago
Aurora180,529180,968181,490181,127View city insights, Aurora
Joliet150,490152,701152,798152,329View city insights, Joliet
Naperville149,566153,834153,305152,119View city insights, Naperville
Rockford148,946145,783142,145137,547View city insights, Rockford
Elgin114,834114,752115,476115,402View city insights, Elgin
Springfield114,506112,413111,181108,920View city insights, Springfield
Peoria113,264110,980109,754107,447View city insights, Peoria
Waukegan89,30988,30187,53886,462View city insights, Waukegan
Champaign88,31791,46192,05593,195View city insights, Champaign

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