| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Kallistrate | - | Ancient Greek | ||
| Kambujiya | - | Ancient Persian | ||
| Karl | KAHRL (German, Danish, English, Finnish) | German, Swedish, Norwegian, Danish, English, Finnish, Ancient Germanic | ||
| Karpos | - | Ancient Greek, Biblical Greek | ||
| Kassandra | kə-SAN-drə (English) | Greek Mythology, Ancient Greek, English (Modern) | ||
| Kassandros | - | Ancient Greek | ||
| Ketill | - | Ancient Scandinavian | ||
| Ketilri&Eth;R | - | Ancient Scandinavian | ||
| Khshayarsha | - | Ancient Persian | ||
| Kleisthenes | - | Ancient Greek | ||
| Kleitos | - | Ancient Greek | ||
| Kleon | - | Ancient Greek | ||
| Kleopatra | - | Ancient Greek | ||
| Kleopatros | - | Ancient Greek | ||
| KnÚTr | - | Ancient Scandinavian |