- Illaunaclaggin
- Illaunawhilla
- Illaunbaun
- Illaunbeg
- Illaunhobert
- Illaunloo
- Illaunmore
- Illaunmore
- Illaunonearaun
- Inagh
- Inis Bhig
- Inishcorker
- Inishdadroum
- Inishdea
- Inishloe
- Inishmacnaghtan
- Inishmacowney
- Inishmarry
- Inishmore
- Inishparran
- Inishtubbrid
- Islandovanna
- Ightermurragh
- Ileclash
- Illane
- Illanebeg
- Illaunbweeheen
- Inch
- Inch
- Inchamay