| Kristiina | | KREES-tee:-nah (Finnish) | Finnish, Estonian | |
| Kristoffer | | KREES-tof-fer (Finnish) | Swedish, Norwegian, Danish, Finnish | |
| Kukka | | KOOK-kah | Finnish | |
| Kustaa | | KOOS-tah: | Finnish | |
| Kusti | | KOOS-tee | Finnish | |
| KyÖSti | | KUY-uus-tee | Finnish | |
| Kylli | | KUYL-lee | Finnish | |
| Kyllikki | | KUYL-leek-kee (Finnish) | Finnish, Finnish Mythology | |
| Lahja | | LAHH-yah | Finnish | |
| Laila (2) | | LIE-lah | Danish, Norwegian, Swedish, Finnish | |
| Lari | | LAH-ree | Finnish | |
| Lars | | LAHSH (Swedish, Norwegian), LAHRS (Danish, Finnish) | Swedish, Norwegian, Danish, Finnish, Dutch, German | |
| Lasse | | LAHS-se (Danish, Finnish) | Swedish, Norwegian, Danish, Finnish | |
| Lassi | | LAHS-see | Finnish | |
| Launo | | - | Finnish (Rare) | |