- Mount Auburn
- Mount Ayr
- Mount Carmel
- Mount Clare
- Mount Etna
- Mount Hamill
- Mount Joy
- Mount Joy Mobile Home Park
- Mount Lucia
- Mount Pleasant
- Mount Sterling
- Mount Union
- Mount Vernon
- Mount Zion
- Moville
- Mt Pleasant
- Mt Vernon
- Municipal Island
- Munterville
- Murphy
- Murray
- Murray Island
- Muscatine
- Muscatine Island
- Muscatine Island
- Mystic