St. Mary County ZIP Codes
Louisiana, United States · 10 codes
St. Mary County in Louisiana has 10 ZIP codes, from 70340 to 70540, serving 10 places.
ZIP codes in St. Mary
Frequently asked questions
What is the ZIP code of St. Mary?
St. Mary has 10 ZIP codes, from 70340 to 70540. The table lists the places each one serves.
How many places are listed in St. Mary County?
10 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.