Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Manor Run | Stream | | Montgomery | 39 06 38 N | 077 06 17 W |
| Manor School (historical) | School | 22 | Cecil | 39 29 15 N | 075 50 39 W |
| Manor Springs | Populated Place | 119 | Baltimore | 39 27 05 N | 076 31 33 W |
| Manor View | Populated Place | 140 | Baltimore | 39 27 36 N | 076 31 35 W |
| Manor View Elementary School | School | 65 | Anne Arundel | 39 06 42 N | 076 44 26 W |
| Manor View Farms | Populated Place | 188 | Baltimore | 39 33 08 N | 076 33 49 W |
| Manor Village | Populated Place | 93 | Frederick | 39 18 53 N | 077 28 50 W |
| Manor Visitor Center | Locale | 181 | Frederick | 39 35 15 N | 077 26 06 W |
| Manor Woods | Populated Place | 114 | Baltimore | 39 26 41 N | 076 31 36 W |
| Manor Woods Elementary School | School | 151 | Howard | 39 17 23 N | 076 54 46 W |
| Manresa | Populated Place | 7 | Anne Arundel | 39 00 23 N | 076 29 25 W |
| Manresa Pond | Bay | 1 | Anne Arundel | 39 00 23 N | 076 29 20 W |
| Mansfield Monument | Park | 153 | Washington | 39 28 56 N | 077 44 29 W |
| Mansfield Woods | Populated Place | 9 | Baltimore | 39 18 27 N | 076 26 49 W |
| Mansion House Manor | Populated Place | 19 | Anne Arundel | 39 07 42 N | 076 32 14 W |
| Mantua | Populated Place | 110 | Baltimore | 39 30 18 N | 076 44 39 W |
| Manufacturing Training Center | Building | | Queen Anne's | 38 57 03 N | 076 05 08 W |
| Manumsco Creek | Stream | | Wicomico | 38 23 19 N | 075 48 50 W |
| Many Fork Branch | Stream | | Anne Arundel | 38 52 33 N | 076 33 08 W |
| Maple Crest | Populated Place | 16 | Baltimore | 39 20 54 N | 076 26 24 W |
| Maple Crest | Populated Place | 277 | Carroll | 39 32 22 N | 076 59 04 W |
| Maple Dam (historical) | Dam | 0 | Dorchester | 38 30 59 N | 076 04 52 W |
| Maple Glen Cemetery | Cemetery | 704 | Garrett | 39 42 22 N | 079 09 03 W |
| Maple Glen School | School | 40 | Anne Arundel | 39 05 43 N | 076 46 55 W |
| Maple Grove | Populated Place | 249 | Carroll | 39 38 57 N | 076 51 37 W |
| Maple Grove Church | Church | 699 | Garrett | 39 42 18 N | 079 09 01 W |
| Maple Grove Church | Church | 117 | Howard | 39 14 26 N | 076 50 35 W |
| Maple Haven | Populated Place | 204 | Carroll | 39 27 25 N | 076 58 46 W |
| Maple Lick Run | Stream | | Garrett | 39 28 39 N | 079 11 30 W |
| Maple Plains | Populated Place | 11 | Wicomico | 38 23 14 N | 075 34 30 W |
| Maple Ridge | Populated Place | 66 | Anne Arundel | 39 04 21 N | 076 41 34 W |
| Maple Run | Populated Place | 37 | St. Mary's | 38 16 20 N | 076 32 22 W |
| Maple Run | Stream | | Allegany | 39 34 58 N | 078 31 51 W |
| Maple School | School | 3 | Dorchester | 38 32 24 N | 076 05 34 W |
| Maple Trailer Park | Populated Place | 64 | Howard | 39 09 39 N | 076 47 35 W |
| Maple View | Populated Place | 272 | Carroll | 39 33 32 N | 076 59 02 W |
| Maple View Baptist Church | Church | 66 | Harford | 39 28 12 N | 076 20 54 W |
| Maple Village (subdivision) | Populated Place | 12 | Caroline | 38 58 29 N | 075 48 53 W |
| Maplecrest Farm | Locale | 145 | Frederick | 39 20 14 N | 077 37 56 W |
| Maplehurst Country Club | Locale | 618 | Allegany | 39 38 30 N | 078 54 54 W |
| Maplehurst Woods | Populated Place | 205 | Baltimore | 39 35 04 N | 076 38 57 W |
| Mapleside United Methodist Church | Church | 221 | Allegany | 39 38 06 N | 078 45 01 W |
| Maplesville Farms | Locale | 170 | Frederick | 39 28 42 N | 077 11 59 W |
| Mapleville | Populated Place | 187 | Washington | 39 32 20 N | 077 38 51 W |
| Maplewood | Populated Place | 150 | Howard | 39 18 22 N | 076 51 49 W |
| Maplewood | Populated Place | 91 | Montgomery | 39 00 27 N | 077 06 12 W |
| Maplewood (subdivision) | Populated Place | 96 | Frederick | 39 24 20 N | 077 25 05 W |
| Mar-Lu-Ridge Conference and Educational Center | School | 341 | Frederick | 39 18 58 N | 077 31 50 W |
| Mar-Lu-Ridge Vista | Populated Place | 150 | Frederick | 39 20 38 N | 077 30 29 W |
| Marabrooke | Populated Place | 34 | Anne Arundel | 39 00 25 N | 076 33 09 W |
| Maranatha Pentecostal Assembly | Church | 16 | Baltimore (city) | 39 19 03 N | 076 32 58 W |
| Marantha Bible College | School | 29 | Cecil | 39 35 37 N | 075 51 53 W |
| Marantha Brethren Church | Church | 165 | Washington | 39 38 25 N | 077 40 40 W |
| Marantha School | School | 24 | Cecil | 39 35 41 N | 075 51 56 W |
| Marbella | Populated Place | 60 | Charles | 38 39 08 N | 076 53 28 W |
| Marbeth Hill (subdivision) | Populated Place | 237 | Carroll | 39 35 00 N | 077 00 24 W |
| Marble Hill | Populated Place | 94 | Baltimore | 39 29 45 N | 076 39 02 W |
| Marble Hill | Populated Place | 51 | Howard | 39 11 50 N | 076 44 32 W |
| Marble Quarry Campground | Locale | 64 | Montgomery | 39 10 46 N | 077 29 34 W |
| Marbury | Populated Place | 26 | Charles | 38 34 31 N | 077 09 20 W |
| Marbury Baptist Church | Church | 27 | Charles | 38 34 08 N | 077 09 13 W |
| Marbury Cemetery | Cemetery | 27 | Charles | 38 34 08 N | 077 09 12 W |
| Marbury Church of God | Church | 43 | Charles | 38 33 55 N | 077 09 12 W |
| Marbury Post Office | Post Office | 23 | Charles | 38 34 19 N | 077 09 19 W |
| Marbury Run | Stream | | Charles | 38 34 59 N | 077 09 36 W |
| Mardela Middle and High School | School | 7 | Wicomico | 38 27 55 N | 075 44 49 W |
| Mardela Apostolic Church | Church | 10 | Wicomico | 38 27 26 N | 075 44 03 W |
| Mardela Springs | Populated Place | 8 | Wicomico | 38 27 35 N | 075 45 33 W |
| Mardela Springs Fire Department and Emergency Medical Services Station 9 | Building | | Wicomico | 38 46 14 N | 076 16 14 W |
| Mardela Springs Park | Park | 0 | Wicomico | 38 27 13 N | 075 45 24 W |
| Mardela Springs Post Office | Post Office | 8 | Wicomico | 38 27 35 N | 075 45 37 W |
| Mardella Branch | Stream | | Baltimore | 39 21 08 N | 076 49 06 W |
| Mardella Run | Populated Place | 141 | Baltimore | 39 21 33 N | 076 49 13 W |
| Mardella Springs Town Hall | Building | 8 | Wicomico | 38 27 43 N | 075 45 28 W |
| Mares Branch | Stream | | Wicomico | 38 24 18 N | 075 46 49 W |
| Margaret Brent School | School | 35 | Prince George's | 38 57 51 N | 076 52 56 W |
| Margate | Populated Place | 14 | Anne Arundel | 39 10 03 N | 076 35 43 W |
| Margate | Populated Place | 137 | Baltimore | 39 29 22 N | 076 26 29 W |
| Margots Island | Island | -3 | Worcester | 38 23 41 N | 075 08 04 W |
| Maria Acres | Populated Place | 17 | Wicomico | 38 23 55 N | 075 31 08 W |
| Marian Fathers Novititate | Church | 142 | Montgomery | 39 10 12 N | 077 03 20 W |
| Mariellen Park | Populated Place | 50 | Charles | 38 30 24 N | 076 57 17 W |
| Marietta Manor Historic Site | Park | 48 | Prince George's | 38 57 58 N | 076 47 57 W |
| Marina Park | Park | 5 | Cecil | 39 36 10 N | 075 49 56 W |
| Marine Channel | Channel | -4 | Anne Arundel | 39 12 45 N | 076 30 41 W |
| Marine Oak Village | Populated Place | 12 | Baltimore | 39 18 58 N | 076 26 55 W |
| Mariners | Populated Place | 1 | Somerset | 37 59 21 N | 075 49 50 W |
| Mariners Cemetery | Cemetery | 2 | Somerset | 37 59 23 N | 075 49 50 W |
| Mariners Cove | Populated Place | 13 | Anne Arundel | 38 59 40 N | 076 30 34 W |
| Mariners Cove | Populated Place | 20 | Cecil | 39 33 38 N | 075 52 16 W |
| Mariners Point (subdivision) | Populated Place | 4 | Anne Arundel | 38 57 18 N | 076 29 02 W |
| Mariners United Methodist Church | Church | 1 | Somerset | 37 59 22 N | 075 49 50 W |
| Maring Manor | Populated Place | 186 | Carroll | 39 35 48 N | 077 03 59 W |
| Marion | Populated Place | 1 | Somerset | 38 02 21 N | 075 46 15 W |
| Marion Baptist Church | Church | 1 | Somerset | 38 02 22 N | 075 46 02 W |
| Marion Burk Knott Auditorium | Building | 174 | Frederick | 39 40 49 N | 077 21 04 W |
| Marion Elementary School | School | 1 | Somerset | 38 02 03 N | 075 45 50 W |
| Marion High School | School | 1 | Somerset | 38 02 22 N | 075 45 52 W |
| Marion Oaks | Populated Place | 27 | Calvert | 38 41 52 N | 076 34 14 W |
| Marion Post Office | Post Office | 1 | Somerset | 38 02 25 N | 075 45 53 W |
| Marion School (historical) | School | 133 | Cecil | 39 37 47 N | 076 01 12 W |
| Marion Volunteer Fire Department | Building | | Somerset | 38 03 34 N | 076 18 09 W |
| Maritime Institute Heliport | Airport | 53 | Anne Arundel | 39 12 40 N | 076 40 19 W |
| Maritime Marine Training School | School | 52 | Anne Arundel | 39 12 45 N | 076 40 16 W |
| Mark Twain Special School | School | 129 | Montgomery | 39 05 42 N | 077 07 21 W |
| Market Place Shopping Center | Locale | | Anne Arundel | 38 58 40 N | 076 29 14 W |
| Market Quay (subdivision) | Populated Place | 7 | Anne Arundel | 38 58 40 N | 076 30 08 W |
| Market Slip | Locale | 3 | Anne Arundel | 38 58 36 N | 076 29 09 W |
| Market Square North | Populated Place | 141 | Howard | 39 18 13 N | 076 51 45 W |
| Market Square South | Populated Place | 144 | Howard | 39 18 05 N | 076 51 58 W |