| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| KateŘIna | - | Czech | ||
| Katka | KAHT-kah | Czech, Slovak | ||
| KazimÍR | - | Czech, Slovak, Hungarian | ||
| KlÁRa | - | Hungarian, Czech, Slovak | ||
| Klaudie | - | Czech | ||
| Klement | - | Czech, Slovak | ||
| KonrÁD | - | Hungarian, Czech, Slovak | ||
| KornÉLie | - | Czech | ||
| Kornel | KAWR-nel (Polish) | Polish, Czech, Slovak | ||
| KristÝNa | - | Czech | ||
| Kristina | kris-TEE-nah (German) | Swedish, Norwegian, Danish, Russian, German, Slovene, Czech, Lithuanian, Serbian, Croatian, Faroese, | ||
| KryŠTof | - | Czech | ||
| Kveta | - | Czech | ||
| LÍDa | - | Czech | ||
| LÝDie | - | Czech |