| Name |
Pronunciation |
Meaning |
English Spelling |
Gender |
| Labraid, Labhraidh | (LOW-ree) | "speaker" | | M |
| Lachtíne, Lachténe, Lachtín | (LOCH-teen) | "milk-coloured" | | M |
| Lachtnae, Lachtna | (LOCHT-na) | "milk-coloured" | | M |
| Lachtnán, Lachtnéne, Lachtnán | (LOCHT-nawn) | dim. of Lachtna | | M |
| Láebán, Laobhán | (LEY-vawn) | "crooked, oblique" | | M |
| Láechrí, Laochra | (LAY-chra) | "king of warriors" | | M |
| Láegaire, Laoghaire, Laoire | (LAIR-ee) | "calf-herd" | Leary | M |
| Laidcenn, Laidgenn, Laidhgeann | (LEE-gan) | "snow-head" | | M |
| Laídech, Laoidheach | (LEE-ach) | "songful, poetic" | | M |
| Laignech, Laighneach | (LYN-ach) | a Leinsterman | Lynagh | M |
| Laígsech, Laoighseach, Laoiseach | (LEE-sach) | man of Laois | Lysagh | M |
| Láimsech, Láimhseach | (LAV-sach) | | | F |
| Laisre | (LOS-ra) | from lassar, "flame, fire" | | M |
| Laisrén, Laisreán | (LOS-rawn) | dim. of Laisre | | M |
| Laithche | (LA-hee) | | | F |
| Lallóc, Lalóg | (LA-lowg) | | | F |
| Lassar, Lasair | (LOS-er) | "flame, fire" | | F |
| Lassar Fhína, Lasairíona | (LOS-er-EE-na) | "fire of wine" | Lasrina | F |
| Lebarcham, Leabharcham | (LOWR-cham) | "slender, stooped" | | F |
| Ledbán, Leadhbhán | (LAY-vawn) | "plaintive" | | M |
| Lennán, Leannán | (LEN-awn) | "lover, sweetheart" | Lennan | M |
| Lerben, Learbhean | (LAR-van) | "lady of the sea" | | F |
| Líadan, Líadain, Líadaine | (LEE-a-dawn) | "grey lady" | | F |
| Líadnán, Liadhnán | (LEE-a-nawn) | "grey lad" | | M |
| Liamuin, Liamhain | (LEE-a-vin) | "comely" | | F |
| Lí Ban, Lí Bhan, Líobhan | (LEE-von) | "beauty of women" | | F |
| Life | (LEE-fa) | person whom River Liffey was named after | Annalivia | F |
| Lígach, Líoghach, Líoch | (LEE-ach) | lustrous, beautiful |
Leah | F |
| Líthgen, Líthghein | (LEE-an) | líth "festival" + gein "birth" | | M |
| Lóch, Lúach | (LOCH) | bright, radiant | | M,F |
| Lóchíne, Lóchéne, Lóchán,
Luachán | (LOCH-awn) | dim. of Lóch, bright, radiant | | M |
| Lochlainn | (LUK-lin) | probably "Viking" | Lachlan | M |
| Loimsech, Loimseach | (LIM-sach) | from lomm "bare" | | M |
| Loingsech, Loinseach | (LIN-sach) | seafarer, exile | Lynch, Lindsay | M |
| Lommán, Lomán | (lum-AWN) | from lomm "bare" | Loman | M |
| Lonán | (lun-AWN) | lon "blackbird" | | M |
| Lonngargán, Lonargán | (LUN-arg-awn) | lonn "bold, eager" + garg "rough, fierce" | Lonergáin, Lonergan | M |
| Lonnóg | (lun-OWG) | lonn "bold, eager" | | F |
| Lorccán, Lorcán | (LUR-kawn) | lorcc "silent" or "fierce" - common in Medieval Ireland | Lorcan | M |
| Lúarán | (LOOR-awn) | lúar "fierce" | Loran | M |
| Lúcás | (LOO-kaws) | biblical name Luke | Luke | M |
| Lug, Lugh | (LOO) | light, brightness - Celtic god | | M |
| Lugach, Lughach | (LOO-ach) | perhaps from Lugh | | F |
| Lugáed, Lughaodh | (LOO-ay) | Lug + Áed | | M |
| Lugaid, Lughaidh, Lúí | (LOO-ee) | derived from Lug | | M |
| Lugán, Lughán | (LOO-awn) | dim. of Lug | | M |
| Lugna, Lughna | (LOO-na) | dim. of Lug - rare | | M |
| Luthigern, Luighthighearn, Lúithiarn | (LOO-hiarn) | Lug + tigern "a lord" | | M |
| Luigsech, Luighseach, Luíseach | (LEE-sach) | derived from Lug, "radiant girl" |
Lisa | F |