| 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 | |
| Concettina | | kon-chet-TEE-nah | Italian | |
| Concetto | | kon-CHET-to | Italian | |
| Consolata | | kon-so-LAH-tah | Italian | |
| Cornelia | | kawr-NE-lee-ah (German), kor-NE-lyah (Italian), kawr-NAY-lee-ah (Dutch), kər-NEE-lee-ə (English), kər-NEEL-yə (English) | German, Romanian, Italian, Dutch, English, Ancient Roman | |