County ZIP codes · Missouri · FIPS 29189
St. Louis County, MO ZIP Codes
St. Louis County, Missouri has 55 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 47 residential and 8 for PO boxes or a single organization. 43 of the residential ones lie mainly in St. Louis County and 4 mainly in a neighboring county; 15 cross the county line. Median household income ranges from $35,176 in 63120 to $225,493 in 63131 (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of St. Louis County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $61,624 and $120,177.
They carry 15 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 47 residential ZIP codes in St. Louis County
43 ZIP codes lie mainly in St. Louis County; 4 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 63021 | Ballwin | 55,666 | 2,551 | $120k | $350k | 100% |
| 63129 | Saint Louis | 51,553 | 2,466 | $95k | $296k | 100% |
| 63031 | Florissant | 50,196 | 3,333 | $71k | $154k | 100% |
| 63123 | Saint Louis | 49,077 | 3,941 | $77k | $219k | 95% |
| 63017 | Chesterfield | 43,243 | 2,245 | $127k | $466k | 100% |
| 63033 | Florissant | 43,056 | 3,544 | $67k | $174k | 100% |
| 63122 | Saint Louis | 41,634 | 2,875 | $136k | $474k | 100% |
| 63136 | Saint Louis | 40,929 | 3,750 | $41k | $84k | 96% |
| 63011 | Ballwin | 35,920 | 2,518 | $125k | $401k | 100% |
| 63119 | Saint Louis | 34,181 | 4,077 | $106k | $351k | 99% |
| 63114 | Saint Louis | 33,969 | 3,845 | $56k | $117k | 100% |
| 63125 | Saint Louis | 33,294 | 3,353 | $62k | $179k | 99% |
| 63146 | Saint Louis | 30,678 | 1,977 | $85k | $302k | 100% |
| 63128 | Saint Louis | 30,540 | 1,952 | $92k | $339k | 100% |
| 63130 | Saint Louis | 28,910 | 5,736 | $86k | $316k | 98% |
| 63121 | Saint Louis | 25,008 | 3,693 | $43k | $96k | 100% |
| 63043 | Maryland Heights | 21,924 | 1,747 | $92k | $228k | 100% |
| 63141 | Saint Louis | 20,932 | 1,425 | $134k | $621k | 100% |
| 63005 | Chesterfield | 19,779 | 542 | $199k | $702k | 97% |
| 63137 | Saint Louis | 19,684 | 2,781 | $43k | $83k | 85% |
| 63025 | Eureka | 19,508 | 467 | $126k | $392k | 57% |
| 63034 | Florissant | 18,908 | 1,009 | $104k | $239k | 100% |
| 63105 | Saint Louis | 18,875 | 7,508 | $116k | $766k | 96% |
| 63135 | Saint Louis | 18,381 | 2,962 | $52k | $107k | 100% |
| 63138 | Saint Louis | 18,233 | 984 | $56k | $139k | 99% |
| 63131 | Saint Louis | 17,935 | 1,316 | $226k | $778k | 100% |
| 63042 | Hazelwood | 17,813 | 1,720 | $50k | $149k | 100% |
| 63074 | Saint Ann | 15,793 | 4,032 | $52k | $133k | 100% |
| 63126 | Saint Louis | 15,452 | 3,361 | $99k | $306k | 100% |
| 63132 | Saint Louis | 14,283 | 2,746 | $87k | $417k | 100% |
| 63134 | Saint Louis | 13,059 | 1,575 | $45k | $95k | 100% |
| 63124 | Saint Louis | 10,839 | 1,214 | $194k | $989k | 100% |
| 63044 | Bridgeton | 10,324 | 618 | $78k | $238k | 100% |
| 63144 | Saint Louis | 9,505 | 4,174 | $104k | $305k | 100% |
| 63117 | Saint Louis | 9,261 | 3,914 | $91k | $349k | 94% |
| 63143 | Saint Louis | 8,975 | 4,382 | $66k | $236k | 74% |
| 63040 | Wildwood | 8,526 | 1,931 | $133k | $427k | 100% |
| 63088 | Valley Park | 8,226 | 1,711 | $66k | $247k | 100% |
| 63038 | Wildwood | 7,107 | 341 | $187k | $581k | 100% |
| 63133 | Saint Louis | 6,569 | 2,018 | $39k | $65k | 99% |
| 63127 | Saint Louis | 5,268 | 910 | $123k | $583k | 100% |
| 63140 | Saint Louis | 316 | 601 | $46k | $84k | 100% |
| 63045 | Earth City | no residents | 0 | – | – | 100% |
Partly in St. Louis County
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
17 ZIP codes of St. Louis County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In St. Louis | Elsewhere |
|---|---|---|
| 63123 | 95% | St. Louis city 5% |
| 63026 | 50% | Jefferson County 50% |
| 63136 | 96% | St. Louis city 4% |
| 63119 | 99% | |
| 63125 | 99% | St. Louis city 1% |
| 63130 | 98% | St. Louis city 2% |
| 63005 | 97% | Franklin County 3% |
| 63137 | 85% | St. Louis city 15% |
| 63025 | 57% | Jefferson County 43% |
| 63105 | 96% | St. Louis city 4% |
| 63138 | 99% | St. Louis city 1% |
| 63049 | 20% | Jefferson County 80% |
| 63069 | 33% | Franklin County 43%; Jefferson County 24% |
| 63117 | 94% | St. Louis city 6% |
| 63143 | 74% | St. Louis city 26% |
| 63120 | 6% | St. Louis city 94% |
| 63133 | 99% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do St. Louis County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. St. Louis County's ZIP codes use 2 prefixes: 630 and 631.
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.