Illinois · United States
Decatur population
73,254people · latest figure
Decatur has a population of 73,254, making it the 520th largest place we list in United States. It is in Illinois.
Decatur holds under a tenth of one per cent of United States's 349,035,494 people. New York City, the largest place we list there, is 120 times its size. Twenty years earlier the World Gazetteer recorded 77,868, a fall of 6%.
The 2005 figure comes from the World Gazetteer archive restored on this site. The two sources may draw the settlement's boundary differently, so treat the change as indicative rather than exact. Why figures differ.
Decatur is in Illinois, which has 945 recorded places.
Nearby in size
| Place | Region | Population |
|---|---|---|
| Rapid City | South Dakota | 73,569 |
| Warner Robins | Georgia | 73,490 |
| Rochester Hills | Michigan | 73,424 |
| Southfield | Michigan | 73,156 |
| Saint George | Utah | 72,897 |
| New Britain | Connecticut | 72,808 |
All places in United States → · Illinois →
Figures are the latest available in GeoNames (CC BY 4.0), which draws on national censuses of varying dates — treat them as recent, not same-year. Country totals are UN World Population Prospects 2024 (medium variant) where the UN lists the country separately; the handful it reports under a parent state keep a GeoNames figure and are marked as such. Sources & method.