Mercer County ZIP Codes
Mercer County is a county of Illinois.
- ZIP codes
- 12
- Cities & towns
- 12
- Area codes
- 2
- Land area
- 561 sq mi
Every ZIP code in Mercer County
| ZIP code | City |
|---|---|
| 61231 | Aledo |
| 61260 | Joy |
| 61263 | Matherville |
| 61272 | New Boston |
| 61276 | Preemption |
| 61281 | Sherrard |
| 61412 | Alexis |
| 61442 | Keithsburg |
| 61465 | New Windsor |
| 61466 | North Henderson |
| 61476 | Seaton |
| 61486 | Viola |
We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Mercer County codes above are listed without a column we would have to invent.
Cities and towns in Mercer County
A further 2 places in Mercer County appear in the postal source without a page of its own; their codes are in the table above and each one links to its own page.
Area codes covering Mercer County
Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.
Where Mercer County's ZIP codes sit
- Reference points and footprint
- Not an official NANPA boundary
- Not a USPS delivery area
Scope every ZIP code recorded in Mercer County. Source GeoNames US postal codes (2026-07 postal dump), Census 2024 county Gazetteer (2024 Gazetteer) and geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot). Updated . The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.