| JÓNas | | - | Icelandic | |
| JÓNatan | | - | Icelandic | |
| Jakob | | YAH-kawp (German), YAH-kob (Danish) | German, Swedish, Norwegian, Danish, Icelandic, Dutch, Slovene | |
| JennÝ | | - | Icelandic | |
| Karen (1) | | KAH-ren (Danish), KER-ən (English), KAR-ən (English) | Danish, Norwegian, Icelandic, German, English | |
| KatrÍN | | - | Icelandic | |
| Klara | | KLAH-rah (German, Russian, Polish) | Swedish, Norwegian, Danish, Icelandic, German, Russian, Ukrainian, Polish, Slovene, Croatian | |
| KristÍN | | - | Icelandic | |
| KristjÁN | | - | Icelandic | |
| Kristjana | | - | Icelandic | |
| LÁRa | | LOW-rah | Icelandic | |
| LÁRus | | - | Icelandic | |
| LÚ&Eth;VÍK | | LOODH-veek | Icelandic | |
| Leifur | | - | Icelandic | |
| Lilja | | LIL-yah (Icelandic), LEEL-yah (Finnish) | Icelandic, Finnish | |