Town · Illinois
Cortland, Illinois
Cortland, town, in DeKalb County, Illinois. Cortland had 4,676 residents on July 1, 2025 by the Census Bureau's estimate, up 6.2% since 2020; the 2020 Census counted 4,398 and the ACS 2020-2024 5-year estimates put it at 4,564 (±325). GEOID 1716470.
Residents, July 2025 estimate
4,676
Census Bureau estimate (no margin published)
2020 Census count: 4,398 · ACS 2020-2024: 4,564 ±325
Median household income
$73,971
±$18,270 (90% margin)
Illinois: $83,390
Median home value
$233,200
±$21,922 (90% margin)
Illinois: $263,300
Median gross rent
$1,552
±$364 (90% margin)
Illinois: $1,274
Where is Cortland and what county is it in?
Cortland is a town in DeKalb County, Illinois. It covers 3.6 square miles of land, 1,224 residents per square mile in 2020.
Cortland is in the Chicago-Naperville-Elgin, IL-IN metropolitan statistical area, which takes in 13 counties (Census Bureau delineation, July 2023).
Cortland lies entirely within Cortland Township, a township with its own local government (2020 census blocks).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Cortland, and is it growing?
The Census Bureau estimates that 4,676 people lived in Cortland on July 1, 2025, up 6.2% since 2020, while Illinois shrank 0.8%. The 2020 Census counted 4,398 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 4,564 (±325).
| Measure | Cortland | DeKalb County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 4,564 ±325 | 100,703 | no clear change |
| Households | 1,558 ±134 | 39,550 | +204 |
| Average household size | 2.93 ±0.25 | 2.42 | no clear change |
| Housing units | 1,558 ±134 | 41,678 | no clear change |
Cortland's population since 2000
From 2,066 in 2000 to 4,676 in 2025: up 126.3%. The 2000, 2010 and 2020 figures are census counts, each for Cortland as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Cortland?
The median resident of Cortland is 31.5 years old; 29.0% are under 18 and 7.9% are 65 or older. The largest group is non-Hispanic white residents at 70.0%, then Hispanic or Latino residents (of any race) at 17.2%. 4.3% of residents were born outside the United States.
| Measure | Cortland | DeKalb County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 31.5 ±3.4 | 32.7 | no clear change |
| Under 18 years | 29.0% ±4.4 pts | 21.6% | – |
| 65 years and over | 7.9% ±3.5 pts | 13.9% | – |
| Male | 54.2% ±4.0 pts | 49.7% | – |
| Hispanic or Latino (any race) | 17.2% ±4.6 pts | 14.5% | no clear change |
| White alone, not Hispanic | 70.0% ±6.0 pts | 71.0% | no clear change |
| Black or African American alone, not Hispanic | 5.1% ±2.7 pts | 6.8% | −8.4 pts |
| Asian alone, not Hispanic | 0.7% ±1.1 pts | 2.2% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±0.8 pts | 0.2% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.8 pts | 0.0% | – |
| Two or more races, not Hispanic | 7.1% ±5.2 pts | 4.8% | – |
| Some other race alone, not Hispanic | 0.0% ±0.8 pts | 0.5% | – |
| Born outside the United States | 4.3% ±2.3 pts | 6.4% | no clear change |
| Speak a language other than English at home (age 5+) | 10.2% ±3.3 pts | 12.0% | – |
| Civilian veterans (age 18+) | 3.3% ±1.9 pts | 5.2% | – |
| With a disability | 13.5% ±4.5 pts | 11.1% | – |
| No health insurance coverage | 7.6% ±3.9 pts | 5.1% | no clear change |
| High school graduate or higher (age 25+) | 93.7% ±2.8 pts | 92.2% | – |
| Bachelor's degree or higher (age 25+) | 26.7% ±7.0 pts | 33.0% | no clear change |
| Graduate or professional degree (age 25+) | 10.0% ±4.1 pts | 13.3% | – |
| Lived in the same house a year earlier | 76.1% ±9.5 pts | 82.8% | – |
| Moved from another state in the past year | 3.2% ±4.6 pts | 1.9% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Cortland earn?
Half of Cortland's 1,558 households earn less than $73,971 a year (±$18,270), against $70,724 in DeKalb County and $83,390 in Illinois. In 2015-2019 the median was $104,486 in 2024 dollars, so it fell by $30,515 after inflation.
| Measure | Cortland | DeKalb County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $73,971 ±$18,270 | $70,724 | −$30,515 |
| Mean household income | $96,071 ±$11,194 | $90,834 | – |
| Per capita income | $32,888 ±$3,253 | $36,298 | −$8,280 |
| People below the poverty line | 7.0% ±4.9 pts | 14.8% | – |
| Children under 18 below the poverty line | 7.6% ±10.2 pts | 17.3% | – |
| Households receiving SNAP | 14.7% ±7.5 pts | 14.7% | – |
| Households with a computer | 95.9% ±3.4 pts | 96.4% | – |
| Households with a broadband subscription | 95.3% ±3.5 pts | 92.7% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Cortland?
Owners occupy 78.0% of Cortland's occupied homes and renters 22.0%. The median owner-occupied home is valued at $233,200 by its owner (±$21,922). The median renter pays $1,552 a month including utilities, and 46.9% of renters pay 35% or more of their income on rent.
| Measure | Cortland | DeKalb County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $233,200 ±$21,922 | $243,600 | +$41,089 |
| Median gross rent | $1,552 ±$364 | $1,049 | no clear change |
| Renters paying 35% or more of income on rent | 46.9% ±27.0 pts | 46.3% | – |
| Median monthly owner costs, with a mortgage | $1,919 ±$92 | $1,866 | – |
| Owner-occupied homes | 78.0% ±9.0 pts | 61.4% | no clear change |
| Renter-occupied homes | 22.0% ±9.0 pts | 38.6% | – |
| Housing units | 1,558 ±134 | 41,678 | no clear change |
| Homeowner vacancy rate | 0.0% ±3.0 pts | 0.2% | – |
| Rental vacancy rate | 0.0% ±10.4 pts | 2.6% | – |
| Single-family detached homes | 67.5% ±10.2 pts | 58.2% | – |
| Mobile homes | 0.0% ±2.4 pts | 2.1% | – |
| Built 2020 or later | 0.8% ±1.2 pts | 0.5% | – |
| Built 2010 to 2019 | 5.4% ±3.2 pts | 4.0% | – |
| Built 1939 or earlier | 2.0% ±2.2 pts | 16.0% | – |
| Households with no vehicle | 2.8% ±2.6 pts | 6.4% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is Cortland building?
Builders took permits for 38 new housing units in Cortland in 2025 (38 in single-family houses), 8.1 per 1,000 residents against 1.5 across Illinois.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Cortland work and get to work?
80.0% of Cortland's workers drive alone and 9.6% work from home. The average trip to work takes 25.5 minutes.
| Measure | Cortland | DeKalb County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 72.0% ±6.1 pts | 68.4% | – |
| Unemployment rate | 8.2% ±5.8 pts | 6.8% | – |
| Drove alone to work | 80.0% ±5.6 pts | 74.8% | – |
| Carpooled | 8.1% ±4.1 pts | 9.6% | – |
| Public transportation | 1.9% ±2.5 pts | 0.8% | – |
| Walked | 0.5% ±0.7 pts | 4.2% | – |
| Worked from home | 9.6% ±3.8 pts | 9.3% | +6.3 pts |
| Mean travel time to work | 25.5 min ±4.5 | 26.7 min | −6.4 min |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Cortland?
No census tract lies mostly in Cortland; 3 tracts reach into it (2020 census blocks).
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Cortland) · Census block assignment files
How does Cortland compare with other places in Illinois?
By the Census Bureau's July 2025 estimates, Cortland is the 5,086th-most populous of the 19,476 U.S. incorporated places that have one and the 342nd-most populous of 1,294 in Illinois.
Cortland ranks 764th of 1,380 places in Illinois with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 342nd | 1,294 |
| Growth 2020-2025 (PEP) | 44th | 1,347 |
| Residents per square mile | 538th | 1,383 |
| Median household income | 764th | 1,380 |
| Per capita income | 1,014th | 1,383 |
| Median home value | 449th | 1,379 |
| Median gross rent | 179th | 1,280 |
| Bachelor's degree or higher | 577th | 1,369 |
| Median age | 1,346th | 1,383 |
| Owner-occupied share | 678th | 1,382 |
| Work from home | 623rd | 1,015 |
| Travel time to work | 707th | 1,382 |
Cortland's figures with every place in Illinois (CSV)
Every place in Illinois, sortable · Compare Cortland with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Cortland?
17 of the 57 figures for Cortland on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Cortland are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in Cortland.