I
- (County Galway) Inishbarra
- (County Galway) Inchiquin
- (County Galway) Inchagoill
- (County Galway) Illauneeragh
- (County Galway) Illaunananima
- (County Galway) Illaunamid
- (County Galway) Illaunaleama
- (Mayo County) Illanmaster
- (County Galway) Illaunnacroagh
- (Mayo County) Inishgalloon
- (Roscommon) Islandmore
- (Sligo) Inch Island
- (Sligo) Illanbaun
- (Sligo) Inishbeg
- (Sligo) Inishmore
- (Sligo) Innisfree
- (County Leitrim) Inishmagrath Island
- (County Leitrim) Inisheher
- (County Leitrim) Inishmean
- (County Leitrim) Inishtemple
- (County Leitrim) Inishkeen
- (County Galway) Illaunanaur
- (County Galway) Irichaboy South
- (County Galway) Inchamore
- (County Galway) Inisherk
- (County Galway) Illaunanownim
- (County Galway) Illaungorm
- (County Galway) Illaunarroghnut
- (County Galway) Illaunnagappul
- (County Galway) Illaunmore