| Camilo | | kah-MEE-lo (Spanish) | Spanish, Portuguese | |
| Carina (1) | | kə-REEN-ə (English), kah-REE-nah (German) | English, Portuguese, Spanish, German, Late Roman | |
| Carla | | KAHR-lah (Spanish, German, Dutch), KAHR-lə (English) | Italian, Portuguese, Spanish, Catalan, English, German, Dutch | |
| Carlinhos | | - | Portuguese | |
| Carlito | | kahr-LEE-to (Spanish) | Spanish, Portuguese | |
| Carlitos | | - | Spanish, Portuguese | |
| Carlos | | KAHR-los (Spanish) | Spanish, Portuguese, Catalan | |
| Carlota | | kahr-LO-tah (Spanish) | Spanish, Portuguese | |
| Carmo | | - | Portuguese | |
| Carolina | | kah-ro-LEE-nah (Italian, Spanish), ka-roo-LEE-nə (Portuguese), ker-ə-LIEN-ə (English), kar-ə-LIEN-ə (English) | Italian, Spanish, Portuguese, English, Swedish | |
| 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 | |