Mercer County, IL ZIP codes
There are 13 ZIP codes in Mercer County, IL, in 13 towns, from 61231 to 61486. The largest are 61231 (Aledo), 61281 (Sherrard) and 61486 (Viola).
The county seat is Aledo.
- ZIP codes
- 13
- Towns
- 13
- County seat
- Aledo
- County FIPS
17131- State
- Illinois
- Population
- 15,495
- Median household income
- $74,182
- Land area
- 561 sq mi
- Metro area
- Davenport-Moline-Rock Island
Mercer County ZIP codes by town
Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.
Map of Mercer County ZIP codes
The ZIP codes of Mercer County, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.
Mercer County in numbers
About 15,495 people live in Mercer County, in 6,565 households, the 69th most populous of Illinois's 102 counties. The median household income is $74,182 a year, 11% below the Illinois median of $83,390 (US: $80,734). The median owner-occupied home is valued at $146,700 (44% below the Illinois median), and median gross rent is $786 a month. The median age is 44.7; 20.9% of adults 25 and over hold a bachelor's degree or higher (37.8% across Illinois); the average commute takes 28 minutes.
| Population | 15,495 |
|---|---|
| Households | 6,565 |
| Median age | 44.7 |
| Median household income | $74,182 |
| Median home value | $146,700 |
| Median gross rent | $786 |
| Bachelor's degree or higher | 20.9% |
| Mean commute | 28.1 min |
| Population density | 28 / sq mi |
U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Survey estimates carry margins of error, wider for small places. Sources and methods.
Largest towns in Mercer County
| Town | ZIP codes | Population |
|---|---|---|
| Aledo | 1 | 3,668 |
| New Windsor | 1 | 1,192 |
| Viola | 1 | 899 |
| Alexis | 1 | 814 |
| Sherrard | 1 | 691 |
| Matherville | 1 | 657 |
| New Boston | 1 | 648 |
| Reynolds | 1 | 584 |
| Keithsburg | 1 | 490 |
| Joy | 1 | 387 |
| Seaton | 1 | 228 |
| North Henderson | 1 | 191 |
| Preemption | 1 | 127 |
Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.
Neighbouring counties
Counties that share a ZIP code with Mercer County.
Not sure you are in Mercer County? What county am I in? answers from your location, near a county line included.
Every ZIP code in Mercer County, with figures
| ZIP | City | Type | Population | Median income | Median home |
|---|---|---|---|---|---|
61231 | Aledo , IL | Standard | 4,962 | $70,991 | $147,600 |
61260 | Joy , IL | Standard | 737 | $41,645 | $96,700 |
61263 | Matherville , IL | Standard | 657 | $86,500 | $134,800 |
61272 | New Boston , IL | Standard | 1,437 | $64,167 | $145,900 |
61276 | Preemption , IL | Standard | 88 | $87,750 | $89,000 |
61279 | Reynolds , IL | Standard | 1,015 | $87,656 | $161,500 |
61281 | Sherrard , IL | Standard | 2,520 | $102,639 | $224,000 |
61412 | Alexis , IL | Standard | 1,392 | $82,143 | $117,600 |
61442 | Keithsburg , IL | Standard | 504 | $48,750 | $67,200 |
61465 | New Windsor , IL | Standard | 1,192 | $56,875 | $127,400 |
61466 | North Henderson , IL | Standard | 263 | $73,462 | $90,000 |
61476 | Seaton , IL | Standard | 551 | $88,264 | $122,500 |
61486 | Viola , IL | Standard | 1,330 | $78,889 | $134,800 |
Cite this page
zipcodes.pro. “Mercer County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/il/county/mercer
Underlying data is public domain or openly licensed — sources, vintages and licences.