Union County ZIP Codes

Union County is a county of Ohio.

ZIP codes: 9
Cities & towns: 8
Area codes: 6
Land area: 432 sq mi

Every ZIP code in Union County

430xx–433xx

The complete list of Union County, OH ZIP codes with the city each one delivers to.
ZIP code	City
43007	Broadway
43029	Irwin
43036	Magnetic Springs
43040	Marysville
43041	Marysville
43045	Milford Center
43067	Raymond
43077	Unionville Center
43344	Richwood

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Union County codes above are listed without a column we would have to invent.

Cities and towns in Union County

A further 3 places in Union 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 Union County

Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.

Where Union County's ZIP codes sit

Each point is the reference point of one Union County ZIP code, plotted from its record coordinates. The outline is the convex envelope of those points — a footprint, not a boundary.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope every ZIP code recorded in Union 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 16 July 2026. The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.