Washington County ZIP Codes
Ohio, United States · 20 codes
Washington County in Ohio has 20 ZIP codes, from 45712 to 45789, serving 20 places.
ZIP codes in Washington
Frequently asked questions
What is the ZIP code of Washington?
Washington has 20 ZIP codes, from 45712 to 45789. The table lists the places each one serves.
How many places are listed in Washington County?
20 places.
Source: GeoNames postal codes (CC BY 4.0), geonames.org, retrieved 2026-10-22. Place coordinates are approximate. Check with the national postal service before sending anything valuable.