| Colette | | ko-LET | French | |
| Coline | | - | French | |
| Colombe | | - | French | |
| Constance | | KAHN-stənts (English), kawn-STAWNS (French) | English, French | |
| Constant | | kawn-STAWN (French), KAHN-stənt (English) | French, English (Rare) | |
| Constantin | | kon-stahn-TEEN (Romanian), kawn-stawn-TEN (French) | Romanian, French | |
| Coralie | | - | French | |
| Corentin | | - | Breton, French | |
| Corin | | - | French | |
| Corinne | | ko-REEN (French), kə-REEN (English), kə-RIN (English) | French, English | |
| CornÉLie | | - | French | |
| Corneille | | kor-NAY | French (Archaic) | |
| Cosette | | - | French, Literature | |
| Cosme | | - | Portuguese, French | |
| CunÉGonde | | - | French | |