| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Klaudiusz | KLOWT-yuwsh | Polish | ||
| Klaus | KLOWS (German, Finnish) | German, Danish, Norwegian, Finnish | ||
| Klava | - | Russian | ||
| Klavdija | - | Slovene | ||
| Klavdiya | KLAHV-dee-yah (Russian) | Russian, Ukrainian, Bulgarian | ||
| Klemen | - | Slovene | ||
| Klemens | KLE-mens (German, Polish) | German, Danish, Swedish, Polish | ||
| Klement | - | Czech, Slovak | ||
| Klementina | - | Slovene, Croatian | ||
| Klementyna | kle-men-TI-nah | Polish | ||
| Klim | - | Russian, Ukrainian | ||
| Kliment | klee-MYENT (Russian) | Russian, Ukrainian, Bulgarian, Macedonian | ||
| KnÚTr | - | Ancient Scandinavian | ||
| Knox | NAHKS | English | ||
| Knud | KNOOD | Danish |