- Largy
- Leabgarrow
- Leaght
- Leatbeg
- Leckemy
- Legland
- Legnahoory
- Lehardan
- Lemacraig
- Lenamore
- Lenan
- Lenankeel
- Lergynasearhagh
- Leslie Hill
- Letterbarra
- Lettergull
- Letterkilley
- Letterleague
- Lettermacaward
- Lettermakenny
- Lettermore
- Limestone Brook Bridge
- Linsfort
- Lisavaddy
- Lisclamer
- Liscooly
- Liscooly Bridge
- Lismoghry
- Listack
- Listicall