| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Kaiser | - | Various | ||
| Karina | kah-REE-nah (Swedish, Polish, German, Russian), kə-REE-nə (English) | Swedish, Danish, Norwegian, Polish, German, Russian, English | ||
| Karp | KAHRP | Russian | ||
| Katenka | - | Russian | ||
| Katerina | - | Macedonian, Russian, Bulgarian, Greek, Late Roman | ||
| Katia | KAH-tyah | Russian | ||
| Katsiaryna | - | Belarusian | ||
| Katya | KAH-tyah | Russian | ||
| Kazimir | kah-zee-MEER (Russian) | Russian, Medieval Slavic | ||
| Kesha | - | Russian | ||
| Khariton | - | Russian | ||
| Khasan | - | Chechen, Ossetian, Circassian, Ingush, Tatar, Bashkir | ||
| Kir | KEER | Russian | ||
| Kira (1) | KEE-rah | Russian | ||
| Kirill | kee-REEL | Russian |