| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Klim | - | Russian, Ukrainian | ||
| Kliment | klee-MYENT (Russian) | Russian, Ukrainian, Bulgarian, Macedonian | ||
| Kolya | - | Russian | ||
| Konstantin | KAWN-stahn-teen (German), kahn-stahn-TEEN (Russian) | German, Hungarian, Russian, Serbian, Bulgarian, Macedonian | ||
| Kostya | - | Russian | ||
| Kristina | kris-TEE-nah (German) | Swedish, Norwegian, Danish, Russian, German, Slovene, Czech, Lithuanian, Serbian, Croatian, Faroese, | ||
| Kseniya | KSYE-nee-yah | Russian | ||
| Kuzma | kooz-MAH | Russian |