| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 841 | Lennon | Irish | Surname. | M | |
| 842 | Liam | Irish | The Irish diminutive of the name William. | M | |
| 843 | Lochlain | Irish | Home of the Norse. | M | |
| 844 | Lochlann | Irish | Home of the Norse. | M | |
| 845 | Loman | Irish | Bare. | M | |
| 846 | Lorcan | Irish | Little fierce one. | M | |
| 847 | Loughlin | Irish | Servant. | M | |
| 848 | Lugaidh | Irish | Famous warrior. | M | |
| 849 | Lun | Irish | Strong. | M | |
| 850 | Lunn | Irish | Strong. | M | |
| 851 | Lyam | Irish | Form of William. | M | |
| 852 | Macartan | Irish | Son of Artan. | M | |
| 853 | MacAuliffe | Irish | Son of Olaf. | M | |
| 854 | MacBride | Irish | Son of Bridget 'Bride'. | M | |
| 855 | MacCormack | Irish | Son of Cormac. | M | |
| 856 | MacElroy | Irish | Son of Elroy. | M | |
| 857 | MacMaureadhaigh | Irish | Son of Murray. | M | |
| 858 | MacMurra | Irish | Son of Murray. | M | |
| 859 | MacQuaid | Irish | Son of Quaid. | M | |
| 860 | Madden | Irish | Smalldog Milos. | M | |