| Kazimiera | | kah-zee-MYE-rah | Polish | |
| Kazimierz | | kah-ZEEM-yesh | Polish | |
| Kinga | | KEEN-gah (Polish), KEEN-gaw (Hungarian) | Polish, Hungarian | |
| Klara | | KLAH-rah (German, Russian, Polish) | Swedish, Norwegian, Danish, Icelandic, German, Russian, Ukrainian, Polish, Slovene, Croatian | |
| Klaudia | | KLOWT-yah (Polish) | Polish, Slovak | |
| Klaudiusz | | KLOWT-yuwsh | Polish | |
| Klemens | | KLE-mens (German, Polish) | German, Danish, Swedish, Polish | |
| Klementyna | | kle-men-TI-nah | Polish | |
| Kondrat | | KAWN-draht | Polish (Archaic) | |
| Konrad | | KAWN-raht (German, Polish) | German, Swedish, Norwegian, Danish, Polish, Slovene | |
| Konstancja | | kawn-STAHNTS-yah | Polish | |
| Konstanty | | kawn-STAHN-ti | Polish | |
| Konstantyn | | kawn-STAHN-tin | Polish | |
| Kornel | | KAWR-nel (Polish) | Polish, Czech, Slovak | |
| Kornelia | | kawr-NE-lee-ah (German), kawr-NEL-yah (Polish) | German, Polish | |