| Cassius | | KASH-əs (English), KAS-ee-əs (English) | Ancient Roman, English | |
| Cato (1) | | - | Ancient Roman | |
| Celsus | | - | Ancient Roman | |
| Cicero | | SIS-ə-ro (English) | Ancient Roman | |
| Claudia | | KLAW-dee-ə (English), KLOW-dee-ah (German, Dutch), KLOW-dyah (Italian, Spanish, Romanian) | English, German, Dutch, Italian, Spanish, Romanian, Biblical, Ancient Roman | |
| Claudius | | KLAW-dee-əs (English) | Ancient Roman | |
| Cloelia | | - | Ancient Roman | |
| Cloelius | | - | Ancient Roman | |
| Cnaeus | | - | Ancient Roman | |
| 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 | |
| Cornelius | | kər-NEE-lee-əs (English), kawr-NAY-lee-us (Dutch), kawr-NE-lee-uws (German) | Ancient Roman, English, Dutch, German, Biblical | |
| Crispinus | | - | Ancient Roman | |
| Crispus | | - | Ancient Roman | |
| Cyprianus | | - | Ancient Roman | |
| Decima | | DEK-i-ma | Ancient Roman | |