| Kleopatros | | - | Ancient Greek | |
| Korinna | | - | Ancient Greek | |
| Kosmas | | - | Ancient Greek | |
| Kyriakos | | - | Greek, Ancient Greek | |
| Kyrillos | | - | Ancient Greek | |
| Kyros | | - | Ancient Greek, Biblical Greek | |
| Leon | | LEE-awn (English), LE-awn (German, Polish) | English, German, Polish, Slovene, Croatian, Dutch, Ancient Greek | |
| Leonidas | | - | Greek, Ancient Greek | |
| Leontios | | - | Ancient Greek | |
| Leontius | | - | Ancient Greek (Latinized) | |
| Ligeia | | - | Greek Mythology, Ancient Greek | |
| Linos | | - | Greek Mythology, Ancient Greek | |
| Linus | | LIE-nəs (English), LEE-nuws (German, Swedish) | Greek Mythology (Latinized), Ancient Greek (Latinized), German, Swedish, Norwegian, Danish | |
| Loukianos | | - | Ancient Greek | |
| Lycurgus | | - | Greek Mythology (Latinized), Ancient Greek (Latinized) | |