39521 ZIP Code: Bay Saint Louis, Mississippi
ZIP code 39521 covers Bay Saint Louis, Mississippi. It sits in Hancock County. Bay Saint Louis is covered by 2 ZIP codes in total, so 39521 is one delivery area within it rather than the whole city. A ZIP code is a US Postal Service mail route, not a boundary on a map, so it describes where post is delivered rather than an administrative area.
| ZIP code | 39521 |
|---|---|
| Place | Bay Saint Louis |
| State | Mississippi (MS) |
| County or equivalent | Hancock County |
| ZIP codes covering Bay Saint Louis | 2 |
| Phone area codes in Mississippi | 4 |
| Country | United States |
Other ZIP codes in Bay Saint Louis
ZIP codes near 39521
- 39522 Stennis Space Centerabout 1 mile
- 39529 Stennis Space Centerabout 1 mile
- 39525 Diamondheadabout 7 miles
- 39556 Kilnabout 8 miles
- 39520 Bay Saint Louisabout 8 miles
- 39576 Wavelandabout 10 miles
- 39558 Lakeshoreabout 12 miles
- 39463 Nicholsonabout 12 miles
Distances are straight-line, between the approximate centres of each delivery area.
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Frequently asked questions
Where is ZIP code 39521?
ZIP code 39521 is in Bay Saint Louis, Mississippi, in Hancock County. ZIP codes are mail delivery routes rather than mapped regions, so the code identifies a set of addresses the Postal Service serves together, not a district with fixed borders.
What county is 39521 in?
39521 is in Hancock County, Mississippi. A single ZIP code can straddle a county line, because mail routes were drawn for delivery efficiency and take no notice of county boundaries, so the county shown is the one the code is primarily associated with.
What area code goes with ZIP code 39521?
ZIP codes and telephone area codes are separate systems with different boundaries, so no ZIP code maps to exactly one area code. Mississippi uses 4 geographic area codes: 228, 601, 662 and 769.
How many ZIP codes does Bay Saint Louis have?
Bay Saint Louis, Mississippi has 2 ZIP codes in this dataset, of which 39521 is one. Large cities are split across many codes so mail can be sorted by district, and the codes are usually numerically close to each other.
Is 39521 a real ZIP code?
Yes. 39521 appears in the GeoNames postal-code dataset as an active US code assigned to Bay Saint Louis, Mississippi. Codes that have been retired or never issued do not appear, which is why entering one on this site returns a not-found page rather than a blank record.
Why do ZIP code boundaries look odd on maps?
Because they are not boundaries. A ZIP code is a collection of mail routes, and a route is a line a carrier walks or drives, not an area. Any ZIP code map you have seen is somebody's approximation drawn around the addresses in a code, which is also why two ZIP code maps rarely agree with each other.
Can two addresses in the same ZIP code be in different cities?
Yes, routinely. The Postal Service assigns a preferred city name to each code for addressing purposes, and that name often covers several neighbouring towns, unincorporated areas or a whole postal district. The place shown here is the one the source names for the code, not a claim that every address in it is inside that town's limits.
ZIP code, place, county and location data from GeoNames, used under CC BY 4.0, extracted 2026-08-22. ZIP codes are Postal Service delivery routes, not administrative areas, so a code can cross city and county lines and the place name shown is the one the source records for the code. Coordinates are an approximate centre of the delivery area, not a precise location. Population and time zone are not shown because the source does not publish them.