ZIP codes in St. Mary Parish
11 ZIPs touch St. Mary Parish, Louisiana. The blue dashed line is the county border; orange ZIPs reach into it.
11
ZIP codes
2
cross the county line
58,927
people in these ZIPs
64
counties in LA
Most people
St. Mary Parish ZIP list
More counties in Louisiana
- St. Charles Parish12
- St. Helena Parish7
- St. James Parish9
- St. John the Baptist Parish7
- St. Landry Parish20
- St. Martin Parish9
- St. Tammany Parish22
- Tangipahoa Parish22
- Tensas Parish4
- Terrebonne Parish14
- Union Parish9
- Vermilion Parish13
Questions people actually ask
How many ZIP codes are in St. Mary Parish, Louisiana?
11 ZIP codes reach into St. Mary Parish, including 2 PO Box or single-address ZIPs placed by the town they serve. 2 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in St. Mary Parish has the most people?
70380 (Morgan City) has about 20,529 residents, the most of any ZIP touching St. Mary Parish, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in St. Mary Parish and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in St. Mary Parish. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
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Updated 2026-11-10 · Where the data comes from