| Callias | | - | Ancient Greek (Latinized) | |
| Cassander | | - | Ancient Greek (Latinized) | |
| 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) | |
| Corinna | | kə-REEN-ə (English), kə-RIN-ə (English), ko-RI-nah (German) | English, German, Ancient Greek (Latinized) | |
| Cosmas | | - | Ancient Greek (Latinized) | |
| Cyrillus | | - | Ancient Greek (Latinized) | |
| Cyrus | | SIE-rəs (English) | English, Biblical, Biblical Latin, Ancient Greek (Latinized) | |