There are 10 zip codes in Washington County, Missouri. The most populated is 63664, located in Potosi. * 2024 populations estimated based on the latest ACS 5-year data.

CSV JSON
Zip Code
Population
City
636649,039Potosi
636603,647Mineral Point
636303,512Cadet
630711,353Richwoods
636481,282Irondale
63626941Blackwell
63631774Caledonia
63622726Belgrade
63030289Fletcher
6367424Tiff

Zip Codes in Washington County, Missouri by Population (2024)