ZIP CodesZIP codes in Mercer County, Illinois
Mercer County, Illinois has 12 ZIP codes in this list, from 61231 to 61486. They cover 12 places, among them Aledo, Joy, Matherville and New Boston.
| ZIP code | Place | Land area (sq mi) | Map point |
|---|---|---|---|
| 61231 | Aledo | 153 | 41.201, -90.742 |
| 61260 | Joy | 58.3 | 41.226, -90.852 |
| 61263 | Matherville | 1.4 | 41.260, -90.613 |
| 61272 | New Boston | 89.2 | 41.215, -90.988 |
| 61276 | Preemption | 0.3 | 41.300, -90.587 |
| 61281 | Sherrard | 40.2 | 41.303, -90.494 |
| 61412 | Alexis | 79.8 | 41.052, -90.544 |
| 61442 | Keithsburg | 28.6 | 41.104, -90.926 |
| 61465 | New Windsor | 40.4 | 41.199, -90.460 |
| 61466 | North Henderson | 23.9 | 41.101, -90.474 |
| 61476 | Seaton | 44.5 | 41.073, -90.826 |
| 61486 | Viola | 43.4 | 41.202, -90.594 |
The ZIP code areas of Mercer County add up to about 603 square miles of land (1,563 sq km) as the Census Bureau draws them. The largest is 61231 (Aledo), with 153 square miles.
Using these codes
- In an address, the ZIP code comes last, after the city and the two-letter state: Aledo, IL 61231.
- Tap a ZIP code to open it in the look-up, with a copy button for the address line.
- A code can cross a county line, and one town can have several codes. The table shows the main place of each code.
- "No area" means the Census Bureau draws no area for that code. Such codes are usually for post office boxes or a single building.
Places and counties: GeoNames. Areas: U.S. Census Bureau, 2024 ZIP Code Tabulation Areas. Checked in November 2026. This site is not connected with the United States Postal Service; for mailing, confirm the address with USPS.