M
- (Sligo) Murhy
- (Sligo) Moymlough
- (Sligo) Mullanabreena
- (Sligo) Murillyroe
- (Sligo) Magheraghanrush
- (Sligo) Mullaghgar
- (Sligo) Mullaghfin
- (County Leitrim) Moneyduff
- (County Leitrim) Magurk
- (County Leitrim) Mullagh
- (County Leitrim) Mullanaskeagh
- (County Leitrim) Mullaghdoo
- (Sligo) Mullaghmore
- (Sligo) Mount Town
- (Sligo) Magheralackagh
- (County Galway) Móinín na Ruaige
- (County Galway) Mweenish Island
- (Mayo County) Mweelaun Island
- (County Galway) Mutton Island
- (County Leitrim) Mullaghgarve
- (Mayo County) Mullagh
- (Mayo County) Moyny
- (Roscommon) Moyne
- (Mayo County) Moylaw
- (County Galway) Moyascragh
- (County Galway) Moyard
- (County Galway) Moy
- (Roscommon) Mount Talbot
- (County Galway) Mount Bellew Bridge
- (Roscommon) Moore