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U.S. ZIP Codes Database 2026

Search by ZIP code, city, county, or state and find clear postal details with maps, time zones, and area code data.

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St. Louis County ZIP Codes

Browse all ZIP Codes, cities, and associated area codes registered in St. Louis County.

County State ZIP Code City Area Codes
St. Louis County MO 63074 Saint Ann 314, 557
St. Louis County MO 63088 Valley Park 636
St. Louis County MO 63099 Fenton 636
St. Louis County MO 63105 Saint Louis 314, 557
St. Louis County MO 63114 Saint Louis 314, 557
St. Louis County MO 63117 Saint Louis 314, 557
St. Louis County MO 63119 Saint Louis 314, 557
St. Louis County MO 63121 Saint Louis 314, 557
St. Louis County MO 63122 Saint Louis 314, 557, 636
St. Louis County MO 63123 Saint Louis 314, 557
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About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.