| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Kleisthenes | - | Ancient Greek | ||
| Kleitos | - | Ancient Greek | ||
| Kleon | - | Ancient Greek | ||
| Kleopatra | - | Ancient Greek | ||
| Kleopatros | - | Ancient Greek | ||
| KnÚTr | - | Ancient Scandinavian | ||
| Korinna | - | Ancient Greek | ||
| Kosmas | - | Ancient Greek | ||
| Kunibert | KOO-nee-bert (German) | German, Ancient Germanic | ||
| Kuno | KOO-no (German) | German, Ancient Germanic | ||
| Kurush | - | Ancient Persian | ||
| Kyriakos | - | Greek, Ancient Greek | ||
| Kyrillos | - | Ancient Greek | ||
| Kyros | - | Ancient Greek, Biblical Greek |