Mercer County Illinois is covered by a total of 16 ZIP Codes. There are 9 ZIP Codes in Mercer County that extend into adjacent counties (Henderson County, Henry County, Knox County, Rock Island County, and Warren County). Of the ZIP codes within or partially within Mercer County there are 14 Standard ZIP Codes and 2 PO Box ZIP Codes.
Click on the ZIP Codes in the interactive map to view more information. The map control in the upper right corner can be used to toggle map layers on and off. The red outline is the border of Mercer County and can be turned on and off. Each type of postal code can also be turned on and off.
| ZIP Code | ZIP Code City/Town | ZIP Code Type | |||
|---|---|---|---|---|---|
| Aledo | Standard | |||
| Joy | Standard | |||
| Lynn Center | Standard | |||
| Matherville | PO Box | |||
| Milan | Standard | |||
| New Boston | Standard | |||
| Preemption | PO Box | |||
| Reynolds | Standard | |||
| Sherrard | Standard | |||
| Alexis | Standard | |||
| Keithsburg | Standard | |||
| New Windsor | Standard | |||
| North Henderson | Standard | |||
| Rio | Standard | |||
| Seaton | Standard | |||
| Viola | Standard |