How many people live in Rock Island County, IL?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 142,700 people living in Rock Island County, IL. That makes Rock Island County the 15th-most populous county in Illinois. It is home to 1.1% of people living in the state.
143K
population of Rock Island County, IL (2024)
1.1%
County share of the Illinois population (2024)
About 142,700 people lived in Rock Island County, IL in 2024.
Population estimates, 2000–2024
What are Rock Island County, IL’s age demographics?
About 29,800 Rock Island County, IL residents are aged 65 and older in 2024. That represents 20.9% of its population. For comparison, the age group represents 17.9% of Illinois' population and 18% in the US overall.
Another 31,900 Rock Island County residents, or 22.4% of the population, were children under 18. For comparison, the age group represents 21.2% of Illinois’s population and 21.6% in the US overall.
A higher share of Rock Island County, IL's population is aged 65 or older than the US as a whole.
Population estimates by age group, (2024)
What are Rock Island County, IL’s racial and ethnic demographics?
Non-Hispanic white residents make up 66.7% of the Rock Island County, IL population, higher than the national share of 57.5%. Rock Island County, IL also has a larger share of people identifying as non-Hispanic two or more races (2.9%) than the US overall (2.5%).
In contrast, Rock Island County’s Hispanic population accounts for 14.7%, below the 20% nationwide, and the non-Hispanic Asian population makes up 3% of the county, compared with 6.5% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Rock Island County, IL has a higher share of a non-Hispanic white population than Illinois as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Rock Island County, IL is Moline with about 22,500 residents in 2024.
Cities and towns in Rock Island County, IL ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Moline (pt.) | 22,453 |
| 2. | Moline (pt.) | 19,951 |
| 3. | Rock Island (pt.) | 18,016 |
| 4. | Rock Island (pt.) | 15,670 |
| 5. | East Moline (pt.) | 14,885 |
| 6. | Silvis | 8,003 |
| 7. | East Moline (pt.) | 6,102 |
| 8. | Milan (pt.) | 5,033 |
| 9. | Coal Valley (pt.) | 3,710 |
| 10. | Rock Island (pt.) | 2,508 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
