| Celio | | CHE-lyo (Italian), THE-lyo (Spanish), SE-lyo (Latin American Spanish), SE-lyoo (Portuguese) | Italian, Spanish, Portuguese | |
| Celso | | CHEL-so (Italian), THEL-so (Spanish), SEL-so (Latin American Spanish) | Italian, Spanish, Portuguese | |
| Cesare | | CHE-zah-re | Italian | |
| Cesarina | | che-sah-REE-nah | Italian | |
| Cesarino | | che-sah-REE-no | Italian | |
| Chiara | | kee-AH-rah | Italian | |
| Chiarina | | kee-ah-REE-nah | Italian | |
| Cinzia | | - | Italian | |
| Cipriano | | chee-pree-AH-no (Italian) | Italian, Spanish, Portuguese | |
| Ciriaco | | chee-ree-AH-ko (Italian), thee-ree-AH-ko (Spanish), see-ree-AH-ko (Latin American Spanish) | Italian, Spanish | |
| Cirillo | | chee-REEL-lo | Italian | |
| Cirino | | chee-REE-no (Italian), thee-REE-no (Spanish), see-REE-no (Latin American Spanish) | Italian, Spanish | |
| Ciro | | CHEE-ro (Italian), THEE-ro (Spanish), SEE-ro (Latin American Spanish) | Italian, Spanish | |
| Clara | | KLAH-rah (Italian, German, Spanish), KLER-ə (English), KLAR-ə (English) | Italian, German, Spanish, Portuguese, Catalan, Romanian, English, Swedish, Danish, Late Roman | |
| Claretta | | - | Italian | |