Illinois Population 2024

Illinois population

Illinois has the fifth largest population in USA with population close to 12.8 million, which accounts for 3.9% of the US population. It is also the 12th most densely populated state in US behind California. The state’s capital city is Springfield but the largest city by population in Illinois is Chicago with population close to 2.7 million. The state is known as “Land of Lincoln” and “Prairie State”.

The state is located in the center-east of the America. It has a total area of 149,932 km2 which ranks 25th largest state in terms of land size in US. Illinois is bordered by Wisconsin to the north, Michigan via a water boundary in Lake Michigan to north east; Indiana to the east; Kentucky to south east, the Mississippi River forms a natural border with Missouri and Iowa to the west.

Based on our research, Illinois population will reach 12.817 million by 1st July of 2024. We use first day of July each year due to US census bureau normally publishes the estimated population data for the same period. The calculation is based on the average growth rate of -0.03% over last 12 years since 2011. We believe using the recent years’ figures (see the table in next section) will make the estimation more accurate.

Population Growth of Illinois

Looking back last twelve years of Illinois’s population, the growth rate is not very promising ranging from -0.23% to 0.08%, adding around losing around 30,000 to adding 10,000 people each year to the overall population The growth stops since 2014. Last three years, it has recorded negative growth due to lack of opportunities in the state. Comparing with other US states, Illinois population growth rate is below the average and one of the slowest growth states in the country. 

Year Population (millions) Growth rate
2011 12.86 n/a
2012 12.87 0.08%
2013 12.88 0.08%
2014 12.88 0.00%
2015 12.86 -0.16%
2016 12.83 -0.23%
2017 12.81 -0.16%
2018 12.82 0.08%
2019 12.81 -0.08%
2020 12.79 -0.12%
2021 12.791 0.01%
2022 12.80 0.03%
2023 12.820 0.02%

Demographics of Illinois

According to U.S. Census Bureau, 49.04 percent of the Illinois population is male and 50.96 percent are female. Average male age is 35 and average female age is 37, so average state age is 36.

The top five races for people living in Illinois are: White(77.29%),Black(14.68%),Asian(5.5%),Native(0.06%),Two or more races (1.87%).

The top five languages (other than English) spoken in Illinois are: Spanish (13.06%), Chinese (0.55%), German (0.38%), French (0.29%) and Kru, Ibo, Yoruba (0.15%). As you can see Spanish dominate the non-English speaking Language due to Latin American immigrant population.

The religious makeup of Illinois is: Catholic(29%),No religion(15%),Baptist(11%),Christian(7%),Lutheran(7%),Methodist(6%),Not specified(4%),Other(3%). Roman Catholics constitute the single largest religious denomination in Illinois; they are heavily concentrated in and around Chicago, and account for nearly 30% of the state’s population.

Population Density of Illinois

Illinois’s population density is 89 people per square kilometer, which is ranking 12th most populated state in US just after California. Compared with the most populous density state, Illinois is close to 5 times less density than New Jersey. 

Position State Population Density (per m2)
1 New Jersey 470
2 Rhode Island 394
3 Massachusetts 336
4 Connecticut 286
5 Maryland 238
6 Delaware 187
7 New York 162
8 Florida 145
9 Pennsylvania 110
10 Ohio 109
11 California 97
12 Illinois 89

Top 5 Largest Cities by Population          

The population figures below are based on the estimated by United States Census. They are subject to change. We will endeavor to make the figures as accurate as possible.

Chicago – Being the most populous city in Illinois and 3rd largest city by population in US, it is also the 3rd densely populated major city in the United States, the city has over 2.7 million people that accounts for 21.73% of the state population. Almost a quarter of the state population is living in Chicago due to the job opportunities there. The city’s population density is 4,593 people per km2 … read more about Chicago population 2023.

Aurora– The city has the second largest population in Illinois with population around 201,000 that accounts for 1.57% of the state population. Aurora has nick names of “City of Lights”. The city population is far behind the population of Chicago, almost 10 times less than Chicago… read more about Aurora population 2023.

Joliet– It is located 64 km southwest of Chicago with population over 148,000 that accounts for 1.16% of the state population. It ranks the third most populous city in Illinois after Chicago and Aurora. It is known as “City of Steel”, “City of Stone”, “City of Champions” and “Prison City”.

Rockfort– The city has population over 147,000 that accounts for 1.14% of the state population. The city’s population is the fourth biggest in Rockfort behind Chicago, Aurora and Joliet. During 2017, a special census was completed putting the population at 153,379.

Naperville– The city has population over 147,000 that accounts for just 1.14% of the state population. Naperville’s population is only a fraction less than the population of Rockfort. Naperville was ranked as the wealthiest city in the Midwest and the eleventh wealthiest in the nation. It has a motto of “Great Service – All the Time.

Facts About Illinois

  1. Illinois was the first state to ratify the 13th amendment to abolish slavery.
  2. Three U.S. presidents have been elected while living in Illinois: Abraham Lincoln, Ulysses S. Grant, and Barack Obama.
  3. The Nabisco factory in Chicago is the world’s largest bakery in the world at 1,800,000 square feet!
  4. Illinois generates more nuclear power than any other state.
  5. Aurora is known as the  City of Lights because it was the first U.S. city to use electric street lighting throughout the entire city.
  6. American scholars previously thought the name “Illinois” meant “man” or “men” in the Miami-Illinois language.
  7. The Lincoln Park Zoo in Chicago is one of only three major free zoos in the county, and is the nation’s oldest public zoo.
  8. The Lincoln Park Zoo in Chicago is one of only three major free zoos in the county, and is the nation’s oldest public zoo.


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