- Mabel
- Macedonia
- Machesney Park
- Mackinaw
- Mackinaw Dells
- Mackville
- Macomb
- Macon
- Macoupin
- Macoupin Island
- Madison
- Madison Station
- Madonnaville
- Maeystown
- Magnet
- Magnolia
- Magnolia Corner
- Mahomet
- Maizetown
- Makanda
- Malden
- Malibu Bay
- Mallard Creek
- Mallard Lake Estates
- Mallard Lake North
- Mallard Lake South
- Malta
- Malvern
- Mammoth Springs
- Manchester