| Code | Name | Region |
|---|---|---|
| USUTE | Custer | WI |
| USCUF | Cut And Shoot | TX |
| USCTB | Cut Bank | MT |
| USUOF | Cut Off | LA |
| USUTC | Cutchogue | NY |
| USH8B | Cuthbert | GA |
| USCUG | Cutler | CA |
| USXUT | Cutler | IL |
| US2CU | Cutler | IN |
| USC6B | Cutler Bay | FL |
| USCI4 | Cutler Ridge | FL |
| USCUJ | Cuyahoga Falls | OH |
| USCU5 | Cuyahoga Heights | OH |
| USYDL | Cyclone | WV |
| USYJA | Cynthiana | IN |
| USCAZ | Cynthiana | KY |
| US6CY | Cynthiana | OH |
| USCYQ | Cypress | CA |
| US4CY | Cypress | FL |
| USCYX | Cypress | TX |
| USQCU | Cumberland Furnace | TN |
| USCMG | Cumming | GA |
| USIUU | Cumming | IA |
| USC9U | Cummington | MA |
| USUKM | Cunningham | KS |
| USCUO | Cupertino | CA |
| USKUR | Currie | NC |
| USCU8 | Curryville | PA |
| USIUC | Curtice | OH |
| USICU | Curtis | NE |
| USUSB | Curtis Bay, Baltimore | MD |
| USTSS | Curtiss | WI |
| USCUI | Curwensville | PA |
| US8CU | Cushing | ME |
| USCUH | Cushing | OK |
| USXHW | Cushing | TX |
| USJWS | Cusseta | AL |
| USUSR | Custar | OH |
| USUSE | Custer | SD |
| USUTR | Custer | WA |
| USULB | Culbertson | NE |
| USQUB | Culebra | NM |
| USUDN | Cullen | LA |
| USUOZ | Culleoka | TN |
| USCUL | Cullman | AL |
| USCN4 | Culloden | WV |
| USUOH | Cullowhee | NC |
| USAAR | Culpeper | VA |
| USKUV | Culver | IN |
| USCV8 | Culver | OR |