| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 601 | KyndMryn | Welsh | Legendary son of Ermid. | M | |
| 602 | Kynedyr | Welsh | Legendary son of Hetwn. | M | |
| 603 | Kynlas | Welsh | Legendary son of Kynan. | M | |
| 604 | Kynon | Welsh | Legendary son of CIydno. | M | |
| 605 | Kynwal | Welsh | Legendary son of Caw. | M | |
| 606 | Kynwyl | Welsh | Name of a saint. | M | |
| 607 | Kywrkh | Welsh | Legendary son of Cleddyv. | M | |
| 608 | Leoline | Welsh | Variant of Llewellyn: Leader. Lion-like. | M | |
| 609 | Lew | Welsh | Variant of Llewellyn: Leader. Lion-like. | M | |
| 610 | Lewellyn | Welsh | Lionlike. Leader. | M | |
| 611 | Lilybet | Welsh | God's promise. | F | |
| 612 | Linette | Welsh | Variant of ancient Welsh given name Eluned: From 'cilun' meaning idol. | F | |
| 613 | Linnet | Welsh | Variant of ancient Welsh given name Eluned: From 'cilun' meaning idol. | F | |
| 614 | Llacheu | Welsh | Legendary son of Aahur. | M | |
| 615 | Llara | Welsh | Meek. | M | |
| 616 | Llassar | Welsh | Legendary son of Llassar Llaes. | M | |
| 617 | Llawr | Welsh | Legendary son of Erw. | M | |
| 618 | Llevelys | Welsh | Legendary son of Beli. | M | |
| 619 | LlewelIyn | Welsh | Lion. | M | |
| 620 | Llewellyn | Welsh | Leader. Lion-like. | M | |