| Leutwin | | - | Ancient Germanic | |
| 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 | |
| Linza | | - | Ancient Germanic | |
| Liupold | | - | Ancient Germanic | |
| Lothar | | LO-tahr (German) | German, Ancient Germanic | |
| Loukianos | | - | Ancient Greek | |
| Ludolf | | LOO-dawlf (German) | German, Dutch, Ancient Germanic | |
| Ludovicus | | - | Ancient Germanic (Latinized) | |
| Luitgard | | - | German, Ancient Germanic | |
| Lutgardis | | - | Ancient Germanic (Latinized) | |
| Lycurgus | | - | Greek Mythology (Latinized), Ancient Greek (Latinized) | |
| Lycus | | - | Greek Mythology (Latinized), Ancient Greek (Latinized) | |
| Lykos | | - | Greek Mythology, Ancient Greek | |