M
- (County Galway) Mira
- (County Galway) Montpelier
- (County Galway) Menlough
- (County Galway) Moyglass
- (County Galway) Moat Bridge
- (County Galway) Muckanagh
- (County Galway) Meeneen
- (County Galway) Moorfield Cross Roads
- (County Galway) Mullagh
- (Roscommon) Mounthussey
- (Roscommon) Mount Florence
- (County Galway) Moyrus
- (County Galway) Mutton Island
- (County Galway) Malivey
- (Mayo County) Maum
- (Mayo County) Mweewillin
- (Mayo County) Mweelin
- (Mayo County) Moynish More
- (Mayo County) Muckinish
- (Mayo County) Massbrook Lower
- (Mayo County) Middletown
- (Mayo County) Muckanagh
- (Mayo County) Meelick
- (Mayo County) Mullaghawny
- (Sligo) Muingwore
- (Mayo County) Muingnahalloona
- (Mayo County) Moyrahan
- (Mayo County) Muingerroon Bridge
- (Mayo County) Muingingaun
- (Mayo County) Muingrevagh