Illinois has an official population of 12,719,141 residents as of the U.S. Census Bureau’s most recent estimate, ranking it the 6th most populous state in the country. Illinois added 16,108 people during the latest reporting year, marking its third straight year of population growth after a decade of decline.
Population of Illinois 2026 – Introduction
Illinois Population in 2026 sits just under 12.72 million, and the state is no longer shrinking the way it was for most of the 2010s. Illinois held the line as the sixth-largest state in America, behind California, Texas, Florida, New York, and Pennsylvania. Chicago anchors the state’s population base, but the real story this year is regional: the collar counties around Chicago are gaining residents while dozens of downstate counties keep losing them. Anyone researching Illinois Population trends in 2026 needs to look past the single headline number and into the age, race, gender, and migration data that explain why the state grew this year at all.
Illinois’ population story runs on three moving parts: births minus deaths, people crossing state lines, and people arriving from other countries. Right now, international migration is doing almost all the heavy lifting. Domestic outmigration remains stubborn, and Illinois ranks third in the nation for residents leaving for other states. Yet the state still posted a net gain last year, a detail that surprises a lot of people who assume Illinois is emptying out. The sections below break down exactly who lives in Illinois in 2026, where they live, and what’s driving the numbers up and down at the same time.
ILLINOIS POPULATION 2026 — QUICK SNAPSHOT
Total Residents .............. 12,719,141
National Rank ................ #6 of 50
Median Age ................... 39.0 years
Annual Growth (latest yr) ... +16,108 (+0.13%)
Largest City ................. Chicago
Total Counties ............... 102
Interesting Facts About Illinois Population 2026
| Fact | Data Point |
|---|---|
| Total Population | 12,719,141 |
| National Rank | #6 most populous state |
| Median Age | 39.0 years |
| Gender Split | 50.6% female, 49.4% male |
| Largest City | Chicago, 2,731,585 residents |
| Largest County | Cook County, 5,182,090 residents |
| Population Density | 229 people per square mile |
| Consecutive Growth Years | 3rd straight year of growth |
| Domestic Migration Rank | 3rd-worst net outmigration in the US |
| Hispanic Population Share | 18.8% of residents |
Illinois crossed an important threshold this reporting cycle: it has now grown for three consecutive years, a reversal after nearly a decade of population loss following 2014. The turnaround is not driven by locals staying put. It is driven almost entirely by people arriving from outside the country, which is now offsetting the tens of thousands of Illinoisans who move to other states every year. That single dynamic explains most of what shows up in the tables below.
The state also carries a demographic footprint that skews slightly older and more urban than the national average. 39.0 years median age puts Illinois close to the U.S. median of 38.9 years, but the population is heavily concentrated in the northeastern corner of the state. Roughly 40% of all Illinois residents live in Cook County alone, and almost three-quarters of the state’s population lives in the greater Chicago metropolitan footprint. That concentration shapes everything from school funding to legislative redistricting.
Illinois Population 2026: Total Residents and Historical Growth Trend
ILLINOIS POPULATION TREND (2020-2026)
2020 |############################ 12.80M
2021 |########################### 12.70M
2022 |########################## 12.61M
2023 |########################## 12.63M
2024 |########################### 12.70M
2025 |########################### 12.72M
2026 |########################### 12.74M (est.)
| Year | Total Population | Year-over-Year Change |
|---|---|---|
| 2020 | 12,795,348 | — |
| 2021 | 12,703,354 | -91,994 |
| 2022 | 12,609,577 | -93,777 |
| 2023 | 12,633,389 | +23,812 |
| 2024 | 12,703,033 | +69,644 |
| 2025 | 12,719,141 | +16,108 |
| 2026 (estimate) | ~12,735,000 | +15,900 (projected) |
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2025); Federal Reserve Bank of St. Louis (FRED) economic data series
The table shows a state that hit bottom around 2022 and has been climbing back since. Illinois Population fell by roughly 186,000 people between 2020 and 2022, largely tied to pandemic-era moves and accelerated departures to lower-tax states. The rebound that started in 2023 has added back close to 110,000 residents over three years, though the state still sits below its 2020 count. The 2026 figure listed here is a forecast built on the current trendline and is not yet a confirmed Census Bureau release, since official vintage-year figures typically post in December of the following year.
What stands out is how small the recent annual gains are relative to the state’s overall size. An increase of 16,108 people sounds substantial until you divide it against a base of over 12.7 million residents, which works out to 0.13% annual growth. That is far below the growth rates of states like Texas or Florida, and it means Illinois’ population recovery remains fragile. A shift in federal immigration policy or a spike in domestic outmigration could tip the state back into decline within a single reporting cycle.
Illinois Population by Age Group in 2026
ILLINOIS POPULATION BY AGE GROUP 2026
Under 15 |######### 18.5%
15-29 yrs |########## 20.0%
30-64 yrs |####################### 45.8%
65-84 yrs |####### 13.7%
85 and up |# 2.0%
| Age Group | Share of Population | Estimated 2026 Population |
|---|---|---|
| Under 15 years | 18.5% | ~2,356,000 |
| 15 to 29 years | 20.0% | ~2,547,000 |
| 30 to 64 years | 45.8% | ~5,833,000 |
| 65 to 84 years | 13.7% | ~1,745,000 |
| 85 years and older | 2.0% | ~255,000 |
Source: U.S. Census Bureau, American Community Survey 5-Year Estimates
Illinois’ age structure looks like a wide middle with narrower ends. Nearly 46% of residents fall into the 30-64 working-age bracket, which is the group that keeps the state’s tax base and labor force running. The under-15 share sits at 18.5%, a number that has been trending downward for years as birth rates fall statewide, mirroring a national pattern. Fewer young children in the pipeline today means a smaller pool of future working-age adults down the road, a concern demographers at the Illinois Department of Public Health have flagged directly in population projection reports.
At the other end, residents 65 and older now make up close to 16% of the state, split between the 65-84 group and a smaller 85-plus cohort. This senior population is growing faster than any other age bracket in percentage terms, driven by the aging Baby Boomer generation moving through their late 60s and 70s. That shift carries real budget consequences for Medicaid, long-term care facilities, and property tax relief programs, since Illinois’ senior population draws more heavily on state services than any other age group.
Illinois Population by Gender in 2026
ILLINOIS POPULATION BY GENDER 2026
Female |######################### 50.6%
Male |######################## 49.4%
| Gender | Population Share | Estimated 2026 Population |
|---|---|---|
| Female | 50.6% | ~6,444,000 |
| Male | 49.4% | ~6,291,000 |
Source: U.S. Census Bureau, American Community Survey 5-Year Estimates
Women outnumber men in Illinois by roughly 153,000 people, putting the state’s gender ratio at about 97.6 males for every 100 females. That gap is not evenly distributed across age groups. Among children under age 5, boys outnumber girls by a small margin, which is typical and reflects a slightly higher male birth rate nationwide. The pattern flips hard by retirement age: in the 60-64 bracket, women outnumber men by more than 24,000, and by age 85 and older, women outnumber men by nearly two to one.
That widening gap in older age brackets comes down to life expectancy. Women in Illinois live longer on average than men, so the senior population skews increasingly female the further up the age ladder you go. This has direct implications for healthcare planning, since it means demand for widow-focused housing, elder care, and survivor benefits will keep climbing as the Baby Boomer generation ages into its 70s and 80s over the next decade.
Illinois Population by Race and Ethnicity in 2026
ILLINOIS POPULATION BY RACE & ETHNICITY 2026
White |############################### 58.1%
Hispanic/Latino |########## 18.8%
Black |####### 13.3%
Asian |### 5.9%
Multiracial |## 3.4%
Other/Native Am. | 0.5%
| Race / Ethnicity | Share of Population | Estimated 2026 Population |
|---|---|---|
| White | 58.1% | ~7,392,000 |
| Hispanic or Latino (any race) | 18.8% | ~2,394,000 |
| Black or African American | 13.3% | ~1,693,000 |
| Asian | 5.9% | ~751,000 |
| Multiracial | 3.4% | ~433,000 |
| Native American / Other | 0.5% | ~64,000 |
Source: U.S. Census Bureau, American Community Survey 5-Year Estimates
The racial and ethnic makeup of Illinois is shifting even while the overall population barely moves. White residents remain the largest group at 58.1%, but that share has been shrinking every year, with the white population losing nearly 298,000 people since the 2020 Census. The Black population has followed a similar downward path, down roughly 49,000 since 2020. Both declines are tied to the same domestic outmigration trend hitting the rest of the state, not to lower birth rates within either community specifically.
Hispanic and Asian residents are the only two groups posting sustained gains. The Hispanic population added 22,866 people in the most recent year alone and has grown by close to 47,000 since 2020, fueled mainly by higher birth rates within that community rather than new arrivals. The Asian population grew by 12,345 in the same period, a gain of nearly 2.9% since the last decennial count. Illinois ranks 10th nationally for share of Hispanic residents and remains more racially diverse than every neighboring state, including Indiana, Missouri, and Wisconsin.
Illinois Population Growth Components 2026: Births, Deaths and Migration
ILLINOIS POPULATION CHANGE BY COMPONENT (2024-2025)
Int'l Migration |###################### +44,800
Natural Increase |##### +10,900
Domestic Migration |###### -40,017
Net Total Change |######## +16,108
| Component | Net Change | Direction |
|---|---|---|
| International Migration | +44,800 | Positive |
| Natural Increase (Births − Deaths) | +10,900 | Positive |
| Domestic Migration | -40,017 | Negative |
| Total Population Change | +16,108 | Net Positive |
Source: U.S. Census Bureau, Population Estimates Program; Illinois Policy Institute analysis of Census data
Break the state’s growth into its three parts and the picture gets a lot clearer. Births outpaced deaths by 10,900, a modest but stable natural increase. International migration added nearly 44,800 new residents, more than four times the natural increase and the single largest driver behind the state’s overall gain. For broader context on how Illinois compares with national migration and settlement patterns, the US Population Statistics report breaks down how international arrivals are reshaping population totals across the entire country, not just in Illinois.
Domestic migration is the drag on all of it. Illinois lost 40,017 residents to other states last year, the third-largest net loss of any state behind only California and New York. Nearly all of that outmigration flows toward lower-tax states in the South and the Sun Belt, and state polling consistently points to high taxes, cost of living, and public safety concerns as the top reasons residents cite for leaving. Without the international migration surge, Illinois would have posted another year of straight population decline, since domestic losses alone outweigh the state’s natural increase by a wide margin.
Largest Cities in Illinois by Population 2026
LARGEST ILLINOIS CITIES BY POPULATION 2026
Chicago |############################## 2.73M
Aurora |## 181K
Naperville |## 153K
Joliet |## 152K
Rockford |## 147K
| City | 2025 Population | State Rank |
|---|---|---|
| Chicago | 2,731,585 | #1 |
| Aurora | 181,505 | #2 |
| Naperville | 153,114 | #3 |
| Joliet | 152,241 | #4 |
| Rockford | 147,384 | #5 |
| Elgin | 115,476 | #6 |
| Springfield | 112,989 | #7 |
| Peoria | 110,920 | #8 |
| Champaign | 91,195 | #9 |
| Waukegan | 87,940 | #10 |
Source: U.S. Census Bureau, City and Town Population Totals
Chicago remains the third-largest city in the entire United States and holds that spot by a wide margin over Houston, the city most often mentioned as a future challenger. Six of Illinois’ ten largest cities sit inside the Chicago metropolitan area, underscoring just how lopsided the state’s population distribution really is. Naperville edged past Joliet in 2024 to claim the third spot statewide, a shift driven by steady suburban housing growth west of Chicago rather than any single large development. Illinois still ranks among the states worth checking against national benchmarks; the Most Populated States in the US report ranks all fifty states side by side and shows exactly how close Illinois sits to slipping out of the top six.
Downstate Illinois tells a different story. Springfield, Peoria, and Champaign are the only non-Chicago-area cities that crack the top ten, and all three have grown slowly or stayed flat compared to the collar-county suburbs. Rockford, once the state’s second-largest city decades ago, has settled into fifth place and continues to face slower growth than its northeastern Illinois counterparts. The pattern across nearly every ranking in this report is the same: growth concentrates around Chicago, while much of the rest of the state holds steady or slowly loses residents.
Illinois Population by County in 2026
LARGEST ILLINOIS COUNTIES BY POPULATION 2026
Cook |############################## 5.18M
DuPage |##### 930K
Lake |#### 714K
Will |#### 701K
Kane |### 517K
| County | 2025 Population | Share of State Total |
|---|---|---|
| Cook County | 5,182,090 | 40.7% |
| DuPage County | 930,024 | 7.3% |
| Lake County | 714,223 | 5.6% |
| Will County | 701,462 | 5.5% |
| Kane County | 517,255 | 4.1% |
| McHenry County | 317,751 | 2.5% |
Source: U.S. Census Bureau, County Population Totals; Illinois state demographic data
Cook County alone holds more people than 32 individual U.S. states, and it accounts for roughly four in every ten Illinois residents. The five counties bordering Cook, known locally as the collar counties, combine for another 3.18 million residents and represent the fastest-growing part of the state. Only 15 of Illinois’ 102 counties posted net population gains between 2020 and 2024, and nearly all of those gainers sit inside or adjacent to the Chicago metro footprint, including Kendall, Champaign, Grundy, McHenry, and Will.
That leaves 55 of the state’s 102 counties losing residents to outmigration in the most recent reporting year alone. Communities like Peoria, Decatur, and Kankakee are dealing with both fewer births than deaths and residents moving away, a combination that compounds population loss year after year. This uneven pattern matters for state funding formulas, since population counts drive everything from school district budgets to legislative district boundaries, and it also shapes how the state’s growing Hispanic population is distributed; national data on Hispanic settlement patterns, including the Percentage of Hispanic Population in US By State report, shows Illinois consistently ranking among the top ten states for Hispanic population share.
Frequently Asked Questions About Illinois Population 2026
What is the population of Illinois in 2026?
Illinois has an official population of 12,719,141 residents based on the U.S. Census Bureau’s most recent estimate, with the 2026 figure trending toward roughly 12.74 million as the year progresses.
Is Illinois losing population in 2026?
No. Illinois has posted three consecutive years of population growth, though the gains are small. The state added 16,108 residents in the most recent 12-month period, driven almost entirely by international migration.
What is the median age in Illinois in 2026?
The median age in Illinois is 39.0 years, slightly above the national median of 38.9 years.
What race makes up the majority of Illinois’ population?
White residents make up the largest racial group in Illinois at 58.1% of the total population, followed by Hispanic or Latino residents at 18.8%.
How many people live in Chicago in 2026?
Chicago’s population stands at 2,731,585, making it the third-largest city in the United States and home to roughly 21% of Illinois’ entire population.
What is the most populated county in Illinois in 2026?
Cook County is the most populated county in Illinois, with 5,182,090 residents, representing about 40.7% of the state’s total population.
Is Illinois still the 6th most populous U.S. state?
Yes. Illinois ranks #6 among all fifty states, a position it has held for years despite slow overall growth.
Why is Illinois’ population growing despite so many people leaving?
Illinois lost 40,017 residents to domestic outmigration last year, but that loss was offset by 44,800 international arrivals and 10,900 more births than deaths, producing a small net gain overall.
What percentage of Illinois is Hispanic in 2026?
Hispanic or Latino residents make up 18.8% of Illinois’ population, or roughly 2.39 million people, ranking Illinois 10th nationally for Hispanic population share.
How many people are moving out of Illinois every year?
Illinois lost more than 40,000 residents to other states in the most recent reporting year, ranking third-worst nationally behind only California and New York for domestic outmigration.
What is Illinois’ population density in 2026?
Illinois has a population density of roughly 229 people per square mile, based on a land area of 55,499 square miles and a population just under 12.72 million.
Will Illinois’ population keep declining relative to other states?
Illinois Department of Public Health projections assume continued net domestic migration losses of around 30,000 people per year through 2035, which puts Illinois at risk of dropping from the 6th to the 8th most populous state by 2040 if current trends hold.
Disclaimer: The data research report we present here is based on information found from various sources. We are not liable for any financial loss, errors, or damages of any kind that may result from the use of the information herein. We acknowledge that though we try to report accurately, we cannot verify the absolute facts of everything that has been represented.
