| Colombe | | - | French | |
| Conall | | - | Irish, Scottish, Irish Mythology | |
| Conrad | | KAHN-rad (English), KAWN-raht (German) | English, German, Ancient Germanic | |
| Constance | | KAHN-stənts (English), kawn-STAWNS (French) | English, French | |
| Constant | | kawn-STAWN (French), KAHN-stənt (English) | French, English (Rare) | |
| Constantijn | | kawn-stahn-TIEN | Dutch | |
| Constantin | | kon-stahn-TEEN (Romanian), kawn-stawn-TEN (French) | Romanian, French | |
| Coos | | KO:S | Dutch | |
| Coralie | | - | French | |
| Corentin | | - | Breton, French | |
| Corin | | - | French | |
| Corinna | | kə-REEN-ə (English), kə-RIN-ə (English), ko-RI-nah (German) | English, German, Ancient Greek (Latinized) | |
| Corinne | | ko-REEN (French), kə-REEN (English), kə-RIN (English) | French, English | |
| Cormag | | - | Scottish | |
| CornÉ | | kawr-NAY | Dutch | |