- Maryland Line
- Marys Choice
- Mayfair
- Mays Chapel North
- Mays Chapel Village
- McDonogh
- McDonogh Manor
- McDonogh Park
- Meadowcliff
- Meadowland
- Merrymans Mill
- Merrymount
- Merrywood
- Miami Beach
- Middleborough
- Middlesex
- Middletown Downs
- Middletown Estates
- Mikules Manor
- Milestone Manor
- Mill Run Estates
- Millgate
- Mission Ridge
- Monkton Farms
- Monumental
- Morgan Manor
- Morningside Heights
- Morrisville
- Mount Carmel
- Mount Carmel Farms