| Casimiro | | - | Spanish, Portuguese, Italian | |
| Cassandra | | kə-SAN-drə (English), kə-SAHN-drə (English), kahs-SAHN-drah (Italian) | English, Spanish, Portuguese, Italian, French, German, Greek Mythology (Latinized) | |
| Catarina | | kah-tah-REE-nah (Italian), ka-ta-REE-na (Galician) | Italian, Portuguese, Occitan, Galician | |
| CecÍLia | | - | Portuguese, Slovak, Hungarian | |
| Cecilio | | the-THEE-lyo (Spanish), se-SEE-lyo (Latin American Spanish), che-CHEE-lyo (Italian) | Spanish, Portuguese, Italian | |
| Celestino | | the-le-STEE-no (Spanish), se-le-STEE-no (Latin American Spanish), che-le-STEE-no (Italian) | Spanish, Italian, Portuguese | |
| 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 | |
| CesÁRia | | - | Portuguese | |
| CesÁRio | | - | Portuguese | |
| CezÁRio | | - | Portuguese (Brazilian) | |
| Cezar | | - | Romanian, Portuguese (Brazilian) | |
| ChÂU | | - | Vietnamese | |
| ChÍ | | - | Vietnamese | |
| Chandra | | - | Hinduism, Bengali, Indian, Assamese, Hindi, Marathi, Telugu, Tamil, Kannada, Nepali | |