| Cleisthenes | | KLIES-thə-neez (English) | Ancient Greek (Latinized) | |
| Cleitus | | - | Ancient Greek (Latinized) | |
| Cleon | | - | Ancient Greek (Latinized) | |
| Cleopatra | | klee-ə-PAT-rə (English) | Ancient Greek (Latinized) | |
| Clitus | | - | Ancient Greek (Latinized) | |
| Clodovicus | | - | Ancient Germanic (Latinized) | |
| Cloelia | | - | Ancient Roman | |
| Cloelius | | - | Ancient Roman | |
| Clothildis | | - | Ancient Germanic (Latinized) | |
| Clovis | | KLO-vis (English), klo-VEES (French) | Ancient Germanic (Latinized), French | |
| Cnaeus | | - | Ancient Roman | |
| Colobert | | - | Ancient Germanic | |
| Conrad | | KAHN-rad (English), KAWN-raht (German) | English, German, Ancient Germanic | |
| Corinna | | kə-REEN-ə (English), kə-RIN-ə (English), ko-RI-nah (German) | English, German, Ancient Greek (Latinized) | |
| 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 | |