Rock Island County, IL: Cities, ZIP Codes & Population
Rock Island County in Illinois (FIPS 17161) contains 16 communities in our dataset. The largest is Moline, IL, and the listed places add up to roughly 126,017 residents. Below you can browse its cities, check its ZIP codes and find nearby counties.
What are the key facts about Rock Island County?
| County | Rock Island County |
|---|---|
| State | Illinois |
| FIPS code | 17161 |
| Places in our data | 16 |
| Places with a city page | 4 |
| Combined place estimates | 126,017 |
| Largest place | Moline, IL (41,356) |
| Rank in state | 15th of 102 counties by combined place population |
| Weighted density | 1,937 per sq mi |
| Time zone | Central time |
| ZIP codes | 18 |
Which cities and towns are in Rock Island County?
Rock Island County has 4 places large enough for a full page on this site. They are ranked below by estimated population, together with whether each is incorporated, its density in people per square mile and the number of ZIP codes it uses. Moline, IL is the largest, followed by Rock Island, IL.
| Place | Type | Population | Per sq mi | ZIPs |
|---|---|---|---|---|
| Moline, IL | Incorporated | 41,356 | 2,468 | 2 |
| Rock Island, IL | Incorporated | 37,176 | 2,201 | 2 |
| East Moline, IL | Incorporated | 20,645 | 1,412 | 3 |
| Silvis, IL | Incorporated | 7,475 | 1,743 | 3 |
The county also contains 12 smaller communities that appear here but do not have separate pages because their populations are too small for reliable data: Milan, Coal Valley, Carbon Cliff, Hampton, Port Byron, Andalusia, Coyne Center, Rapids City, Cordova, Oak Grove, Reynolds, Hillsdale. Residents of these places often depend on the county for services such as roads, courts and public health.
How large is Rock Island County compared with other counties in Illinois?
Adding up the estimates for the places in our data gives 126,017 people, which ranks Rock Island County 15th among 102 counties in Illinois. The average listed place has about 7,876 residents. The weighted density is about 1,937 people per square mile, which is suburban by our scale. These totals add up place estimates, so they can differ from the official county population, which includes people outside any listed place. See why population figures differ.
What ZIP codes are in Rock Island County?
The places in Rock Island County use 18 ZIP codes: 61201, 61204, 61232, 61236, 61239, 61240, 61242, 61244, 61256, 61257, 61264, 61265, 61266, 61275, 61278, 61279, 61282, 61284. Every code begins with 6, which is assigned to the central Midwest (Illinois, Kansas, Missouri and Nebraska). A ZIP code can cross county lines, so a code listed here may also serve addresses in a neighboring county. Use the ZIP code lookup to check a single code, or read how ZIP codes work.
Which counties are near Rock Island County?
The closest counties by distance between the average locations of their places are listed below. The distance is a rough guide to how close the areas are, because county shapes vary widely.
- Scott County, IA — about 11 miles northwest (center to center), 343,932 people in listed places
- Henry County, IL — about 19 miles southeast (center to center), 34,610 people in listed places
- Mercer County, IL — about 26 miles southwest (center to center), 7,577 people in listed places
- Clinton County, IA — about 27 miles north (center to center), 43,531 people in listed places
- Whiteside County, IL — about 34 miles northeast (center to center), 49,600 people in listed places
- Muscatine County, IA — about 35 miles west (center to center), 35,028 people in listed places
What does the FIPS code 17161 mean?
The first two digits, 17, identify Illinois, and the last three, 161, identify Rock Island County inside that state. Government datasets use this code to join records without confusing counties that share a name. Our guide to counties and FIPS codes explains the numbering, and the Illinois hub lists every county we cover in the state.
Where to go next
Combined place populations are estimates from a compiled dataset and are not official county totals.