S
- (Mayo County) Shammerdoo
- (Mayo County) Scregg
- (Mayo County) Shanaghmoyle
- (Mayo County) Sallyhernaun
- (Mayo County) Shanvally
- (Mayo County) Slievenabrehan
- (Mayo County) Spaddagh
- (Mayo County) Scardaun
- (Mayo County) Sonvolaun
- (Mayo County) Speck
- (Mayo County) Shanvaghera
- (Mayo County) Stripe
- (Mayo County) Shammerbaun
- (Mayo County) Sraheens
- (Mayo County) Skeneen
- (Sligo) Seraigh
- (Sligo) Sargirra
- (Sligo) Sralea
- (Sligo) Sragh
- (Sligo) Stoney Island
- (Roscommon) Sracocka
- (Roscommon) Slieveroe
- (Roscommon) Stonepark
- (Roscommon) Silverfield
- (Roscommon) Sheepwalk
- (Roscommon) Southpark Demesne
- (Sligo) Streamstown
- (Sligo) Soodry
- (Sligo) Skreen Beg
- (Sligo) Spring Garden