Illinois Population 2018


The population of Illinois in 2018 is estimated at 12.77 million. The 2015 Census estimates put the population at 12,859,995, which was a decrease from the 2014 numbers.

Illinois is one of only 7 states that has a negative growth rate in 2016. At -0.17% per year, it is ahead of only West Virginia. Between 2000 and 2010, the population of Illinois grew by a mere 3.3%, compared to the national average US population growth of 9.7%.

The 2016 population makes Illinois the fifth largest state in the USA based on population.

Chicago, Largest City in Illinois

Most of the Illinois population is based in the North East of the state. Chicago, home to 2,720,546 people, remains the largest city in Illinois. It dwarfs the state's other cities. The next largest is Aurora, with 200,661 people.

This marks one of Illinois' defining features -- although it has a large urban population, it is spread through a number of smaller cities. Including Chicago, there are twelve cities with more than 75,000 people.

Many of these smaller cities make up a part of the Chicago Metropolitan Area (prosaically also known as Chicagoland), which holds between 8.3 and 9.8 million people, depending on how you classify its boundaries.

Cook County is the largest county in Illinois, housing 5,238,216 people. The next largest county is neighboring Dupage, with 933,736 people. Almost half of the Illinois population can be found in just those two counties.

Illinois Population History

Illinois was included in the Northwest Territory established in 1787 and then in Indiana Territory (1800). Illinois Territory was established in 1809, and included virtually all of present-day Wisconsin and portions of Minnesota and the Upper Peninsula of Michigan. Illinois was admitted as a State on December 3, 1818 with essentially its present boundaries.

In 1790 the Northwest Territory had no census coverage. The population shown for 1800 is the total of two counties and one community in present-day Illinois, at that time part of Indiana Territory. Knox County, Indiana Territory, also included some population in what is now Illinois. In 1810, the returns for the two counties of Illinois Territory included some settlements in present-day Wisconsin. The northern part of the State was not fully covered by the census until 1830.

Illinois Population Chart

Illinois Population History

Illinois saw massive growth throughout the 19th century, from a measley 2,458 people in 1800 to nearly 5 million in 1900. This rise made Illinois the 3rd largest state by the turn of the century. Growth continued into the 20th century, albeit at a slower pace.

Illinois Population Growth

In Illinois' cities, population growth has stalled. Chicago was, for much of its early history, one of America's fastest growing cities. Between 1850 and 1930, the city grew by at least 25% each decade, and in some decades it doubled or even tripled in size. However, from the 1960s onwards, Chicago has been steadily shrinking and a city which was home to 3.5 million people in 1960 is home to just 2.7 million today.

If the current decline continues, Illinois will fall back to the 6th spot in state rankings at the 2020 Census, behind Pennsylvania.

Some estimates expect Illinois to see growth again by 2020, and possibly reach 13.1 million in 2020.

Population Data via US Census

Illinois Growth Rate

Illinois Population Rank

Year Pop % Change

Illinois Facts

Illinois Population in 2018Source: Daniel Schwen

  • Illinois has the world's only river that flows backwards.
  • Chicago's Lincoln Park Zoo is the country's oldest public zoo.
  • Almost 80% of the land in Illinois is farm land.
  • The Sears Tower, located in Chicago, is the tallest building in North America.
  • In 1865, Illinois ratified the 13th Amendment to abolish slavery. It was the first state to do so.
  • There are 102 counties in the state of Illinois.
  • The world's largest public library is the Chicago Public Library, which houses over 2 million books.
  • Chicago was the home of the first aquarium, which opened in 1893.
  • The oldest community in Illinois is Peoria.

Illinois Population Density by County

Cook County

  • Population5,231,356
  • Density5533.88 per sq km
  • Growth Since 20100.61%
  • State Rank1
  • % of State40.76%

Illinois Population Growth Rate by County

When looking at population growth of the state of Illinois by county, the data show that the majority of counties have seen population declines. However, there were still a handful of counties that saw small rates of growth, based on data taken from the 2010 Census and again during 2015 estimates taken by the US Census Bureau. During this 5-year period, Kendall County exhibited the most growth at a rate of 6.98%. Other counties that saw growth during this time period include Kane County at 2.86%, Champaign at 3.66%, and Monroe at 2.63%.

There were far more counties that experienced declines in population. This includes Alexander County, which by far had the biggest decline percentage at over 17%. Other counties with declining populations include Mason at 6.49%, Livinsgton at 5.66%, and Cass at 5.77%, among others.

Illinois Population Pyramid 2018

0k20k40k60k80k100kIllinois Male Population0k20k40k60k80k100kIllinois Female Population80757065605550454035302520151050

To compare Illinois to other states, click here.

Population by Race

Race Population
Black or African American1,813,477
Some Other Race822,784
Two or More Races321,411
American Indian and Alaska Native30,470
Native Hawaiian and Other Pacific Islander4,851

Based on data from the 2010 Census, Illinois has the 14th highest percentage of African Americans across all states. Based on 2011 data, the state also has the 5th highest Hispanic population in the country with over 2 million Hispanic residents, and the 10th highest percentage of Hispanics that account for its total population.

In recent years, Illinois has seen significant declines in its white population, with numbers dropping from 83.5% of the total population in 1970 to 63.3% just 40 years later. According to 2011 data, almost 50% of the population under the age of 1 were minorities.

According to data from 2007, over 1.7 million people in Illinois were foreign-born. This represented, at the time, almost 14% of the population. Over 48% of Illinois' foreign-born inhabitants came from Latin America, while almost one-quarter of the total number came from Asia. It is estimated that over 58% of the total 1.7 million foreign-born inhabitants recorded were not US citizens.

Race Data via US Census (2016 ACS 1-Year Survey)

Languages Spoken in Illinois

Language Population Percentage
Kru, Ibo, Yoruba17,9400.15%

This chart shows the top 10 languages that are spoken at home in Illinois. The data comes from the most recent release of the American Community Survey (ACS).

Illinois Economy

High school graduate or higher 87.6%
Bachelor's degree or higher 31.9%
With a Disability 7%
Persons Without Health Insurance 11.1%
In Civilian Labor Force 65.9%
In Civilian Labor Force (Female) 61%
Food Services Sales $27,937,381
Health Care Revenue $83,431,778,000
Manufacturers Shipments $281,037,755,000
Merchant Wholesaler Sales $295,456,992,000
Total Retail Sales $166,634,514,000
Total Retail Sales per Capita $12,942
Mean Travel Time to Work 28.2 minutes
Median Household Income $57,166
Per Capita Income (past 12 months) $30,019
Persons in Poverty 14.4%

This chart shows the employment and labor force participation rates in Illinois for residents over 16 years of age. The 2015 unemployment rate is 6% and the labor force participation rate is 65.8%.

Illinois Business

Total Nonemployer Establishments 955,153
All firms 1,135,017
Men-owned Firms 609,648
Women-owned Firms 417,500
Minority-owned Firms 311,684
Nonminority-owned Firms 795,129
Veternan-owned Firms 89,110
Nonveteran-owned Firms 1,006,885

Illinois Housing

Housing Units 5,296,715
Owner Occupied Housing Rate 66.9%
Median Value Owner Occupied Housing Units $175,700
Median Monthly Owner Costs (w/Mortgage) $1,676
Median Monthly Owner Costs (no mortgage) $572
Median Gross Rent $903
Building Permits 19,571
Households 4,778,633
Persons per Household 2.63 persons
Living in Same House 1 Year Ago 86.8%
Language Other than English Spoken at Home 22.5%
Data Sources
  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)