| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 421 | Ceallachan | Irish | Variant of Ceallach: War; strife. | M | |
| 422 | Cearbhall | Irish | Manly. | M | |
| 423 | Cearnach | Irish | Victorious. | M | |
| 424 | Cein | Irish | Archaic. | M | |
| 425 | Ceire | Irish | Saint. | F | |
| 426 | Celsus | Irish | Name of a saint. | M | |
| 427 | Chann | Irish | Young wolf. | M | |
| 428 | Channe | Irish | Young wolf. | M | |
| 429 | Channing | Irish | Young wolf. | M | |
| 430 | Channon | Irish | Young wolf. | M | |
| 431 | Chiara | Irish | Dark. Feminine of Ciaran. | F | |
| 432 | Chrissa | Irish | Abbreviation of Christine. Follower of Christ. | F | |
| 433 | Chrissie | Irish | Abbreviation of Christine. Follower of Christ. | F | |
| 434 | Chrissy | Irish | Abbreviation of Christine. Follower of Christ. | F | |
| 435 | Christa | Irish | Servant of Christ. | F | |
| 436 | Christi | Irish | Abbreviation of Christine. Follower of Christ. | F | |
| 437 | Christian | Irish | Servant of Christ. | F | |
| 438 | Christie | Irish | Abbreviation of Christine. Follower of Christ. | F | |
| 439 | Christy | Irish | Abbreviation of Christine. Follower of Christ. | F | |
| 440 | Cian | Irish | Old; ancient; archaic. | M | |