| Clarissa | | klə-RIS-ə (English) | English, Italian, Portuguese, Spanish | |
| Claudia | | KLAW-dee-ə (English), KLOW-dee-ah (German, Dutch), KLOW-dyah (Italian, Spanish, Romanian) | English, German, Dutch, Italian, Spanish, Romanian, Biblical, Ancient Roman | |
| Claudio | | KLOW-dyo | Italian, Spanish | |
| Clelia | | - | Italian | |
| Clemente | | kle-MEN-te (Italian, Spanish) | Italian, Spanish, Portuguese | |
| Clementina | | kle-men-TEE-nah (Italian, Spanish), klə-mən-TEE-nə (Portuguese) | Italian, Spanish, Portuguese | |
| Cleto | | KLE-to (Italian, Spanish) | Italian, Spanish, Portuguese | |
| Clio | | KLEE-o (Italian) | Greek Mythology (Latinized), Italian | |
| Cloe | | - | Spanish, Italian | |
| Clotilde | | klo-TEELD (French) | French, Italian, Portuguese, Spanish | |
| Colomba | | - | Italian | |
| Colombano | | - | Italian | |
| Colombina | | - | Italian | |
| Colombo | | - | Italian | |
| Concetta | | kon-CHET-tah | Italian | |