| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Ceallach | KEL-akh | Irish | ||
| CeallachÁN | - | Irish | ||
| Ceallagh | - | Irish | ||
| Cearbhall | - | Irish | ||
| CennÉTig | - | Irish | ||
| Chevonne | - | Irish | ||
| Christie (2) | - | Scottish, Irish | ||
| Christy (2) | - | Scottish, Irish | ||
| Cian | KEE-an, KEEN | Irish, Irish Mythology | ||
| CianÁN | - | Irish | ||
| Ciannait | - | Irish | ||
| Ciar | KEER, KEE-ar | Irish | ||
| CiarÁN | KEER-awn, KEE-ar-awn | Irish | ||
| Ciara (1) | KEER-a, KEE-ar-a | Irish | ||
| Ciardha | - | Irish |