- Madison
- Manchester
- Mapleville
- Mardela Springs
- Marlboro Meadows
- Marlboro Village
- Marlow Heights
- Marlton
- Martins Additions
- Marydel
- Maryland City
- Maugansville
- Mayo
- Mays Chapel
- McCoole
- Mechanicsville
- Mellwood
- Mercersville
- Middle River
- Middleburg
- Middletown
- Midland
- Midlothian
- Milford Mill
- Millington
- Mitchellville
- Monrovia
- Montgomery Village
- Morningside
- Moscow
- Mount Aetna
- Mount Airy
- Mount Briar
- Mount Lena
- Mount Rainier
- Mount Savage
- Mount Vernon
- Mount Vernon
- Mountain Lake Park
- Myersville
