Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Marlboro Branch Prince George's County Memorial Library | Building | 11 | Prince George's | 38 48 59 N | 076 45 08 W |
| Marlboro Country Club | Locale | 11 | Prince George's | 38 49 35 N | 076 45 44 W |
| Marlboro Heliport | Airport | 3 | Prince George's | 38 48 12 N | 076 44 15 W |
| Marlboro Hills | Populated Place | 37 | Calvert | 38 39 45 N | 076 36 45 W |
| Marlboro Hunt Club | Locale | 4 | Prince George's | 38 48 28 N | 076 42 41 W |
| Marlboro Meadows | Populated Place | 30 | Prince George's | 38 50 10 N | 076 42 54 W |
| Marlboro Speedway | Locale | 4 | Prince George's | 38 48 24 N | 076 44 18 W |
| Marlboro Square Shopping Center | Locale | 6 | Prince George's | 38 48 43 N | 076 44 30 W |
| Marlboro Station | Locale | 7 | Prince George's | 38 49 14 N | 076 44 39 W |
| Marlboro Volunteer Fire Department Stations 20 and 45 | Building | | Prince George's | 39 22 13 N | 077 15 20 W |
| Marlboro Volunteer Fire Department Stations 45 | Building | | Prince George's | 39 22 13 N | 077 15 20 W |
| Marley | Populated Place | 15 | Anne Arundel | 39 09 03 N | 076 35 31 W |
| Marley Creek | Bay | -3 | Anne Arundel | 39 11 12 N | 076 34 42 W |
| Marley Fire Company 18 | Building | | Anne Arundel | 39 09 17 N | 076 35 46 W |
| Marley Glen School | School | 12 | Anne Arundel | 39 08 35 N | 076 35 48 W |
| Marley Heights | Populated Place | 16 | Anne Arundel | 39 09 05 N | 076 35 32 W |
| Marley Junior High School | School | 15 | Anne Arundel | 39 08 58 N | 076 35 43 W |
| Marley Neck | Cape | 12 | Anne Arundel | 39 11 14 N | 076 33 28 W |
| Marley Neck Industrial Park | Locale | 23 | Anne Arundel | 39 10 43 N | 076 32 59 W |
| Marley Neck School (historical) | School | 18 | Anne Arundel | 39 09 42 N | 076 33 55 W |
| Marley Park Beach | Populated Place | 14 | Anne Arundel | 39 09 20 N | 076 35 43 W |
| Marley Run | Populated Place | 21 | Anne Arundel | 39 07 52 N | 076 35 32 W |
| Marley School | School | 14 | Anne Arundel | 39 08 37 N | 076 35 51 W |
| Marley Station (historical) | Locale | 17 | Anne Arundel | 39 08 15 N | 076 36 14 W |
| Marley Station Mall Shopping Center | Locale | 5 | Anne Arundel | 39 08 20 N | 076 36 14 W |
| Marley United Methodist Church | Church | 20 | Anne Arundel | 39 09 12 N | 076 35 34 W |
| Marley Village | Populated Place | 37 | Cecil | 39 37 49 N | 075 52 49 W |
| Marley Volunteer Fire Company Company 18 | Building | | Anne Arundel | 39 15 45 N | 077 00 03 W |
| Marling Farms | Populated Place | 2 | Queen Anne's | 38 55 57 N | 076 15 57 W |
| Marlow Heights | Populated Place | 80 | Prince George's | 38 50 00 N | 076 57 06 W |
| Marlow Heights Park | Park | 83 | Prince George's | 38 50 02 N | 076 56 47 W |
| Marlow Heights Shopping Center | Locale | 81 | Prince George's | 38 50 00 N | 076 56 39 W |
| Marlow Shopping Center | Locale | 85 | Prince George's | 38 50 09 N | 076 56 33 W |
| Marlton | Populated Place | 60 | Prince George's | 38 46 25 N | 076 47 24 W |
| Marlton Community Park | Park | 20 | Prince George's | 38 46 39 N | 076 46 12 W |
| Marlton Elementary School | School | 66 | Prince George's | 38 46 20 N | 076 47 21 W |
| Marlton Neighborhood Park | Park | 55 | Prince George's | 38 45 45 N | 076 47 27 W |
| Marlton Plaza Shopping Center | Locale | 64 | Prince George's | 38 45 36 N | 076 48 25 W |
| Marlton South | Populated Place | 56 | Prince George's | 38 44 43 N | 076 46 60 W |
| Marlywood | Populated Place | 121 | Baltimore | 39 24 04 N | 076 37 12 W |
| Marriots Branch | Stream | | Anne Arundel | 38 55 55 N | 076 35 27 W |
| Marriott Cove | Bay | 2 | Anne Arundel | 39 02 50 N | 076 34 05 W |
| Marriott Hill | Populated Place | 60 | Anne Arundel | 38 52 31 N | 076 36 30 W |
| Marriott Plaza Shopping Center | Locale | 188 | Baltimore | 39 22 52 N | 076 49 19 W |
| Marriottsville | Populated Place | 97 | Howard | 39 21 00 N | 076 53 58 W |
| Marriottsville Post Office | Post Office | 97 | Howard | 39 21 04 N | 076 53 55 W |
| Marriottsville United Methodist Church | Church | 95 | Howard | 39 21 00 N | 076 54 00 W |
| Mars Estates | Populated Place | 11 | Baltimore | 39 19 13 N | 076 26 57 W |
| Mars Estates School | School | 12 | Baltimore | 39 18 51 N | 076 26 57 W |
| Mars Hill Church | Church | 12 | Baltimore | 39 18 54 N | 076 27 22 W |
| Marsden Tract | Area | 38 | Montgomery | 38 58 37 N | 077 13 04 W |
| Marsh Church (historical) | Church | 160 | Washington | 39 35 44 N | 077 44 53 W |
| Marsh Creek | Stream | | Caroline | 38 40 58 N | 075 57 45 W |
| Marsh Gut | Stream | | Somerset | 38 12 37 N | 075 50 47 W |
| Marsh Hill | Summit | 948 | Garrett | 39 32 55 N | 079 22 10 W |
| Marsh Island | Island | 2 | Charles | 38 34 39 N | 077 11 04 W |
| Marsh Point | Cape | 5 | St. Mary's | 38 26 49 N | 076 38 41 W |
| Marsh Run | Stream | | Washington | 39 30 05 N | 077 46 47 W |
| Marsh Run | Stream | 146 | Washington | 39 38 58 N | 077 41 18 W |
| Marsh Run Cove | Bay | 750 | Garrett | 39 32 37 N | 079 21 16 W |
| Marshalee Estates | Populated Place | 79 | Howard | 39 12 24 N | 076 45 37 W |
| Marshall Cemetery | Cemetery | 6 | Charles | 38 41 07 N | 077 05 51 W |
| Marshall Creek | Stream | | Worcester | 38 13 49 N | 075 14 34 W |
| Marshall Ditch | Canal | 3 | Worcester | 38 01 52 N | 075 28 15 W |
| Marshall Hall | Locale | 7 | Charles | 38 40 57 N | 077 05 53 W |
| Marshall Mill Run | Stream | | Worcester | 38 02 31 N | 075 27 09 W |
| Marshall Point | Cape | 0 | Wicomico | 38 25 15 N | 075 50 32 W |
| Marshall Street Education Center | School | 189 | Washington | 39 39 31 N | 077 43 42 W |
| Marshalls Corner | Populated Place | 58 | Charles | 38 32 58 N | 077 02 21 W |
| Marshfield Business Park | Locale | 22 | Baltimore | 39 19 40 N | 076 29 15 W |
| Marshope | Populated Place | 34 | Charles | 38 28 31 N | 077 11 27 W |
| Marshy Creek | Bay | -3 | Queen Anne's | 38 57 25 N | 076 13 45 W |
| Marshy Point | Cape | 4 | Anne Arundel | 38 54 30 N | 076 28 04 W |
| Marshy Point | Cape | 2 | Baltimore | 39 20 06 N | 076 21 25 W |
| Marshyhope Creek | Stream | | Dorchester | 38 31 38 N | 075 45 24 W |
| Marshyhope Village | Populated Place | 3 | Dorchester | 38 37 21 N | 075 49 26 W |
| Marston | Populated Place | 205 | Carroll | 39 30 28 N | 077 06 01 W |
| Marthas Legacy | Populated Place | 173 | Carroll | 39 27 30 N | 076 55 44 W |
| Martin | Populated Place | 173 | Frederick | 39 22 40 N | 077 18 29 W |
| Martin Airport | Airport | 3 | Talbot | 38 48 04 N | 076 15 23 W |
| Martin Bay | Bay | 3 | Worcester | 38 05 44 N | 075 18 22 W |
| Martin Boulevard School | School | 11 | Baltimore | 39 20 06 N | 076 26 28 W |
| Martin Cemetery | Cemetery | 189 | Allegany | 39 37 24 N | 078 23 28 W |
| Martin Cove | Bay | -2 | St. Mary's | 38 12 37 N | 076 27 07 W |
| Martin Lagoon | Bay | -2 | Baltimore | 39 19 33 N | 076 25 37 W |
| Martin Luther King Academic Center Magnet Middle School | School | 55 | Prince George's | 39 03 17 N | 076 54 34 W |
| Martin Luther King Junior Communications Arts Center | Building | | Prince George's | 39 01 04 N | 076 45 43 W |
| Martin Luther King Middle School | School | 171 | Montgomery | 39 11 38 N | 077 14 34 W |
| Martin Luther King Recreational Park | Park | 99 | Montgomery | 39 03 21 N | 076 59 09 W |
| Martin Luther Lutheran Church | Church | 30 | Baltimore (city) | 39 17 44 N | 076 35 06 W |
| Martin Manor | Populated Place | 19 | Harford | 39 25 05 N | 076 17 54 W |
| Martin Mountain | Summit | 515 | Allegany | 39 42 02 N | 078 37 56 W |
| Martin National Wildlife Refuge | Park | 0 | Somerset | 38 01 08 N | 076 01 06 W |
| Martin Plaza Shopping Center | Locale | 12 | Baltimore | 39 20 05 N | 076 26 50 W |
| Martin Point | Cape | 4 | St. Mary's | 38 12 29 N | 076 27 14 W |
| Martin Point | Cape | 0 | Talbot | 38 37 44 N | 076 07 17 W |
| Martin Point | Cape | 0 | Worcester | 38 05 42 N | 075 17 57 W |
| Martin Road Park | Park | 113 | Howard | 39 11 15 N | 076 52 20 W |
| Martin Spaulding High School | School | 32 | Anne Arundel | 39 07 28 N | 076 38 47 W |
| Martin Spring | Spring | 195 | Carroll | 39 38 50 N | 076 59 23 W |
| Martin State Airport | Airport | 5 | Baltimore | 39 19 32 N | 076 24 49 W |
| Martin Sutton Memorial Park | Park | 18 | Caroline | 38 56 29 N | 075 53 10 W |
| Martinak State Park | Park | 6 | Caroline | 38 51 45 N | 075 50 23 W |
| Martindale | Populated Place | 19 | Anne Arundel | 39 08 20 N | 076 35 45 W |
| Martindale | Populated Place | 157 | Harford | 39 34 55 N | 076 22 02 W |
| Martindale Park | Park | 3 | Baltimore | 39 18 21 N | 076 27 19 W |
| Martingham | Populated Place | 3 | Talbot | 38 48 20 N | 076 13 51 W |
| Martini Lutheran Church | Church | 6 | Baltimore (city) | 39 16 46 N | 076 37 04 W |
| Martins Addition | Populated Place | 91 | Montgomery | 38 58 52 N | 077 04 10 W |
| Martins Additions | Populated Place | 103 | Montgomery | 38 58 45 N | 077 04 10 W |