| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| KajetÁN | - | Czech, Slovak, Hungarian | ||
| Kamil (2) | KAH-meel (Polish) | Czech, Slovak, Polish | ||
| Kamila | kah-MI-lah (Czech, Slovak), kah-MEE-lah (Polish) | Czech, Slovak, Polish | ||
| Karol | KAH-rawl (Polish) | Polish, Slovak, Slovene | ||
| KatarÍNa | - | Slovak | ||
| Katka | KAHT-kah | Czech, Slovak | ||
| KazimÍR | - | Czech, Slovak, Hungarian | ||
| KlÁRa | - | Hungarian, Czech, Slovak | ||
| Klaudia | KLOWT-yah (Polish) | Polish, Slovak | ||
| Klement | - | Czech, Slovak | ||
| Koloman | KO-lo-mahn (German) | German (Rare), Slovak | ||
| KonrÁD | - | Hungarian, Czech, Slovak | ||
| Kornel | KAWR-nel (Polish) | Polish, Czech, Slovak | ||
| KriŠTof | - | Slovene, Slovak | ||
| KristÍNa | - | Slovak |