- Maple Leaf Mobile Home Park
- Montague Island
- Morehaven
- Morristown
- Millstadt
- Minier
- Minonk
- Minooka
- Melody
- Monaville
- Moran Corners
- Mylith Park
- Mokena
- Moline
- Momence
- Monee
- Mayo Island
- Meriden
- Milla
- Moores Island
- Maytown
- Morrison
- Morton Grove
- Mount Auburn
- Mount Carroll
- Mount Clare
- Mount Erie
- Mount Prospect
- Mount Pulaski
- Moweaqua