ZIP Codes in Oshkosh, WI
Oshkosh uses 3 ZIP codes, all in Winnebago County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 3 Oshkosh ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 54901 | standard | Winnebago | 37,294 |
| 54902 | standard | Winnebago | 22,243 |
| 54904 | standard | Winnebago | 22,273 |
Finding a ZIP+4 in Oshkosh
Knowing which of these 3 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same Oshkosh street almost always have different ZIP+4 codes even though they share all five leading digits.
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