| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Korneli | - | Georgian | ||
| Kornelia | kawr-NE-lee-ah (German), kawr-NEL-yah (Polish) | German, Polish | ||
| Kornelija | - | Croatian, Serbian | ||
| Kosmas | - | Ancient Greek | ||
| Kosta | - | Bulgarian | ||
| Kostadin | - | Bulgarian, Macedonian | ||
| Kostandin | - | Albanian | ||
| Kostya | - | Russian | ||
| Kostyantyn | - | Ukrainian | ||
| Kotone | ko-to-ne | Japanese | ||
| Kotryna | - | Lithuanian | ||
| Kouki | ko:-kee | Japanese | ||
| Kouta | ko:-tah | Japanese | ||
| Krasimir | - | Bulgarian, Medieval Slavic | ||
| Krasimira | - | Bulgarian |