S
- (County Galway) Stonetown
- (Mayo County) Stonepark
- (Mayo County) Stonefield
- (Mayo County) Srahlaghy
- (Mayo County) Srahduggaun
- (Mayo County) Srah
- (Mayo County) Srah
- (County Leitrim) Slievenakilla
- (Sligo) Skreen
- (County Galway) Skehanagh
- (Roscommon) Shanvally
- (County Galway) Shannaghmore
- (Roscommon) Seltannaveeny
- (County Galway) Seershin
- (County Galway) Scregg West
- (County Galway) Scregg East
- (Roscommon) Scramoge
- (Mayo County) Scardaun
- (Mayo County) Sarnaght
- (County Galway) Salt Hill
- (County Galway) Salrock
- (Mayo County) Salia
- (County Galway) Saint Macdaras Island
- (Sligo) Saint Johns Port
- (County Galway) Straw Island
- (Mayo County) Sonnagh
- (Mayo County) Srah Upper
- (Mayo County) Srah Lower
- (Roscommon) Stag Island
- (Roscommon) Smutternagh