| CIRIL m Slovene |
| CIRILA f Slovene |
| CIRILLO m Italian |
| CIRINO m Italian, Spanish |
| CIRO m Italian, Spanish |
| CY m English |
| CYRIELLE f French |
| CYRIL m English, Czech, Slovak, French |
| CYRILLA f English (Rare) |
| CYRILLE m & f French |
| CYRILLUS m Ancient Greek (Latinized) |
| CYRUS m English, Biblical, Biblical Latin, Ancient Greek (Latinized) |
| CYRYL m Polish |
| KIIRA f Finnish |
| KIR m Russian |
| KIRA (1) f Russian |
| KIRE m Macedonian |
| KIRIL m Bulgarian, Macedonian |
| KIRILL m Russian |
| KIRO m Macedonian |
| KORESH m Biblical Hebrew |
| KURUSH m Ancient Persian |
| KYRA f English |
| KYRILLOS m Ancient Greek |
| KYRILU m Medieval Slavic |
| KYROS m Ancient Greek, Biblical Greek |
| KYRYLO m Ukrainian |
