- Maghera
- Maghera Cross
- Magherabaun
- Magowha
- Mahonburgh Bridge
- Maidens Island
- Martrybeg
- Mary Fort
- Mattle Island
- Mauricemills
- Meelick
- Miltown Malbay
- Moanmore
- Molougha
- Moneen
- Mount Catherine
- Mount Levers
- Mountrivers Bridge
- Mountshannon
- Moveen West
- Moy More
- Moyadda
- Moyarta East
- Moyarta West
- Moyasta
- Moyglass Bridge
- Moymore
- Mullagh
- Murroogh
- Mutton Island