| Claudius | | KLAW-dee-əs (English) | Ancient Roman | |
| Claus | | KLOWS | German, Danish | |
| Cleisthenes | | KLIES-thə-neez (English) | Ancient Greek (Latinized) | |
| Cleitus | | - | Ancient Greek (Latinized) | |
| Clelia | | - | Italian | |
| Clematis | | klə-MAT-is | English (Rare) | |
| Clemency | | KLEM-ənt-see | English (Rare) | |
| Clemens | | KLE-mens (German) | German, Dutch, Swedish, Norwegian, Danish, Late Roman | |
| Clemente | | kle-MEN-te (Italian, Spanish) | Italian, Spanish, Portuguese | |
| Clementia | | - | Late Roman | |
| Clementina | | kle-men-TEE-nah (Italian, Spanish), klə-mən-TEE-nə (Portuguese) | Italian, Spanish, Portuguese | |
| Clementius | | - | Late Roman | |
| Cleon | | - | Ancient Greek (Latinized) | |
| Cleopas | | KLEE-ə-pəs (English) | Biblical, Biblical Latin | |
| Cleopatra | | klee-ə-PAT-rə (English) | Ancient Greek (Latinized) | |