| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 621 | Kyli | Gaelic | Feminine of Kyle. | F | |
| 622 | Kylianne | Gaelic | Feminine of Kyle. | F | |
| 623 | Kylie | Gaelic | Feminine of Kyle. | F | |
| 624 | Kylin | Gaelic | Feminine of Kyle. | F | |
| 625 | Kyna | Gaelic | Intelligent. | F | |
| 626 | Kyran | Gaelic | Dusky; dark-haired. | M | |
| 627 | Kyrell | Gaelic | A place-name referring to the narrows; a wood or a church. | M | |
| 628 | Labhruinn | Gaelic | Laurel. | M | |
| 629 | Lachlann | Gaelic | From Scandinavia. | M | |
| 630 | Lamont | Gaelic | Man of law. | M | |
| 631 | Lamonte | Gaelic | Man of law. | M | |
| 632 | Lana | Gaelic | Diminutive of Alana: This name of uncertain origin may be a feminine form of Man, or derived from the Irish Gaelic word for 'child'. | F | |
| 633 | Laoidheach | Gaelic | From the pasture. | F | |
| 634 | Lawler | Gaelic | One who mumbles. | M | |
| 635 | Leamhnach | Gaelic | Lives near the place abounding in elm trees. | M | |
| 636 | Leannan | Gaelic | Little cloak. | M | |
| 637 | Leitis | Gaelic | Happy. | F | |
| 638 | Lennon | Gaelic | Little cloak. | M | |
| 639 | Lennox | Gaelic | Lives near the place abounding in elm trees. | M | |
| 640 | Lesley | Gaelic | From the gray fortress. | F | |