Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Arlington | Populated Place | 134 | Baltimore (city) | 39 20 22 N | 076 41 02 W |
| Arlington Baptist Church | Church | 135 | Baltimore (city) | 39 20 59 N | 076 40 26 W |
| Arlington Cemetery | Cemetery | 120 | Baltimore (city) | 39 20 39 N | 076 41 49 W |
| Arlington Echo Outdoor Education Center | School | 15 | Anne Arundel | 39 04 37 N | 076 36 24 W |
| Arlington Elementary School | School | 135 | Baltimore (city) | 39 21 01 N | 076 41 04 W |
| Arlington Federal Building | Building | 22 | Baltimore (city) | 39 17 32 N | 076 36 54 W |
| Arlington Methodist Church | Church | 134 | Baltimore (city) | 39 20 39 N | 076 41 09 W |
| Arlington Presbyterian Church | Church | 134 | Baltimore (city) | 39 20 53 N | 076 40 35 W |
| Arlington Station Baltimore Post Office | Post Office | 122 | Baltimore (city) | 39 20 02 N | 076 40 26 W |
| Armacost | Populated Place | 221 | Baltimore | 39 36 48 N | 076 48 14 W |
| Armacost Farms Airport | Airport | 192 | Baltimore | 39 36 12 N | 076 44 40 W |
| Armagh | Populated Place | 120 | Baltimore | 39 22 52 N | 076 37 12 W |
| Armiger | Populated Place | 16 | Anne Arundel | 39 07 30 N | 076 32 05 W |
| Armiger Fire Company 30 | Building | | Anne Arundel | 39 07 55 N | 076 33 47 W |
| Armistead Gardens | Populated Place | 31 | Baltimore (city) | 39 18 06 N | 076 32 58 W |
| Armistead Gardens Presbyterian Church | Church | 29 | Baltimore (city) | 39 18 14 N | 076 33 06 W |
| Armistead Gardens School | School | 32 | Baltimore (city) | 39 18 15 N | 076 33 10 W |
| Armistead Homes | Populated Place | 17 | Baltimore (city) | 39 18 25 N | 076 33 26 W |
| Armistead Monument | Park | | Baltimore (city) | 39 16 48 N | 076 36 31 W |
| Armistead Public School (historical) | School | 16 | Baltimore (city) | 39 16 24 N | 076 36 42 W |
| Armstrong Bay | Bay | -13 | Dorchester | 38 37 15 N | 076 15 53 W |
| Arnold | Populated Place | 39 | Anne Arundel | 39 01 55 N | 076 30 10 W |
| Arnold Churchyard | Cemetery | 38 | Anne Arundel | 39 02 03 N | 076 30 06 W |
| Arnold Elementary School | School | 38 | Anne Arundel | 39 02 05 N | 076 30 13 W |
| Arnold Fire Company 17 | Building | | Anne Arundel | 39 01 43 N | 076 30 12 W |
| Arnold Heights | Populated Place | 84 | Prince George's | 38 51 13 N | 076 56 11 W |
| Arnold Park | Park | 33 | Anne Arundel | 39 02 11 N | 076 29 23 W |
| Arnold Point | Cape | 9 | Anne Arundel | 39 02 06 N | 076 31 49 W |
| Arnold Point | Cape | 2 | Cecil | 39 27 43 N | 075 57 57 W |
| Arnold Post Office | Post Office | 36 | Anne Arundel | 39 01 36 N | 076 30 04 W |
| Arnold Senior Citizens Center | Building | 37 | Anne Arundel | 39 01 52 N | 076 30 14 W |
| Arnold Station Shopping Center | Locale | 38 | Anne Arundel | 39 01 41 N | 076 30 14 W |
| Arnold Volunteer Fire Department | Building | | Anne Arundel | 39 03 23 N | 076 50 32 W |
| Arnold-Asbury United Methodist Church | Church | 42 | Anne Arundel | 39 02 01 N | 076 30 04 W |
| Arnoldtown | Populated Place | 149 | Frederick | 39 24 34 N | 077 36 21 W |
| Aronhalt Fork | Stream | | Garrett | 39 16 53 N | 079 23 30 W |
| Arrington Estates | Populated Place | 187 | Carroll | 39 23 25 N | 076 56 02 W |
| Arrowhead | Populated Place | 99 | Frederick | 39 27 30 N | 077 24 45 W |
| Arrowhead | Populated Place | 95 | Howard | 39 11 15 N | 076 51 44 W |
| Arrowhead Acres | Populated Place | 128 | Cecil | 39 36 08 N | 076 04 24 W |
| Arrowhead Elementary School | School | 79 | Prince George's | 38 51 25 N | 076 50 34 W |
| Arrowhead Farms Estates | Populated Place | 35 | Anne Arundel | 38 58 58 N | 076 41 36 W |
| Arters Mill | Populated Place | 163 | Carroll | 39 39 54 N | 077 04 18 W |
| Arters Mill Estates | Populated Place | 172 | Carroll | 39 41 17 N | 077 04 22 W |
| Arthur Middleton Elementary School | School | 63 | Charles | 38 36 09 N | 076 55 18 W |
| Arthur Ridge | Populated Place | 233 | Carroll | 39 25 02 N | 077 01 39 W |
| Arthur Storer Planetarium | Park | 45 | Calvert | 38 33 10 N | 076 34 59 W |
| Arthurs Run | Stream | 0 | Anne Arundel | 39 01 40 N | 076 33 12 W |
| Arundel | Populated Place | 30 | Cecil | 39 33 57 N | 075 52 23 W |
| Arundel Acres | Populated Place | 60 | Anne Arundel | 39 04 35 N | 076 40 34 W |
| Arundel Beach | Populated Place | 6 | Anne Arundel | 39 04 37 N | 076 31 07 W |
| Arundel Branch | Stream | | Frederick | 39 22 40 N | 077 25 25 W |
| Arundel Church | Church | 9 | Baltimore (city) | 39 12 16 N | 076 34 03 W |
| Arundel Cove | Bay | 0 | Anne Arundel | 39 11 56 N | 076 33 59 W |
| Arundel Crossing East Industrial Park | Locale | | Anne Arundel | 39 05 29 N | 076 41 24 W |
| Arundel Crossing West Industrial Park | Locale | 45 | Anne Arundel | 39 05 25 N | 076 42 10 W |
| Arundel Elementary School | School | 34 | Baltimore (city) | 39 15 07 N | 076 37 40 W |
| Arundel Fire Company 7 | Building | | Anne Arundel | 38 59 21 N | 076 40 14 W |
| Arundel Gardens | Populated Place | 48 | Anne Arundel | 39 12 45 N | 076 37 08 W |
| Arundel Gateway Business Park | Locale | | Anne Arundel | 39 05 38 N | 076 47 38 W |
| Arundel Geriatric and Convalescent Home | Hospital | 12 | Anne Arundel | 39 10 05 N | 076 36 12 W |
| Arundel High School | School | 71 | Anne Arundel | 39 04 18 N | 076 40 55 W |
| Arundel Hills | Populated Place | 47 | Anne Arundel | 39 12 08 N | 076 38 15 W |
| Arundel Hills Park | Park | 36 | Anne Arundel | 39 11 58 N | 076 38 00 W |
| Arundel Middle School | School | 58 | Anne Arundel | 39 04 20 N | 076 41 10 W |
| Arundel Mills Mall | Locale | 51 | Anne Arundel | 39 09 17 N | 076 43 20 W |
| Arundel on the Bay | Populated Place | 3 | Anne Arundel | 38 55 14 N | 076 27 46 W |
| Arundel on the Bay Post Office (historical) | Post Office | 5 | Anne Arundel | 38 55 15 N | 076 27 49 W |
| Arundel Plaza Shopping Center | Locale | 19 | Anne Arundel | 38 58 40 N | 076 32 19 W |
| Arundel Plaza Village Shopping Center | Locale | | Anne Arundel | 39 13 18 N | 076 36 48 W |
| Arundel Ridge | Ridge | 5 | Anne Arundel | 38 59 12 N | 076 37 20 W |
| Arundel View | Populated Place | 62 | Anne Arundel | 39 04 14 N | 076 40 43 W |
| Arundel Village (subdivision) | Populated Place | 42 | Anne Arundel | 39 13 20 N | 076 36 15 W |
| Arundel Village Park | Park | 24 | Anne Arundel | 39 13 33 N | 076 36 19 W |
| Arundel Volunteer Fire Department | Building | | Baltimore (city) | 39 39 30 N | 077 07 01 W |
| Arundel Volunteer Fire Department Company 7 | Building | | Anne Arundel | 39 39 30 N | 077 07 00 W |
| Asberry (historical) | Populated Place | 39 | Anne Arundel | 39 01 37 N | 076 30 19 W |
| Asberry Cemetery | Cemetery | 50 | Calvert | 38 31 06 N | 076 37 08 W |
| Asberry Church | Church | 50 | Calvert | 38 31 06 N | 076 37 08 W |
| Asbury | Populated Place | 7 | Caroline | 38 51 25 N | 075 51 24 W |
| Asbury Cemetery | Cemetery | 123 | Cecil | 39 36 02 N | 076 04 13 W |
| Asbury Cemetery | Cemetery | 124 | Harford | 39 33 02 N | 076 16 06 W |
| Asbury Cemetery | Cemetery | 19 | Kent | 39 15 50 N | 075 53 34 W |
| Asbury Cemetery | Cemetery | 12 | Kent | 39 13 08 N | 076 11 54 W |
| Asbury Cemetery | Cemetery | 2 | Somerset | 37 58 27 N | 075 50 11 W |
| Asbury Cemetery | Cemetery | 3 | Somerset | 38 14 38 N | 075 49 54 W |
| Asbury Church | Church | 9 | Anne Arundel | 39 05 07 N | 076 32 53 W |
| Asbury Church | Church | 128 | Cecil | 39 36 01 N | 076 04 11 W |
| Asbury Church | Church | 125 | Harford | 39 33 01 N | 076 16 06 W |
| Asbury Church | Church | 51 | Howard | 39 08 19 N | 076 48 24 W |
| Asbury Church | Church | 12 | Kent | 39 13 09 N | 076 11 53 W |
| Asbury Church | Church | 18 | Kent | 39 15 57 N | 075 53 36 W |
| Asbury Church | Church | 3 | Wicomico | 38 16 14 N | 075 53 51 W |
| Asbury Church | Church | 7 | Wicomico | 38 20 28 N | 075 36 32 W |
| Asbury Home | Building | 154 | Montgomery | 39 08 47 N | 077 11 50 W |
| Asbury United Methodist Cemetery | Cemetery | 120 | Montgomery | 39 08 31 N | 077 17 50 W |
| Asbury United Methodist Church | Church | 87 | Frederick | 39 24 42 N | 077 24 46 W |
| Asbury United Methodist Church | Church | 7 | Kent | 39 15 31 N | 075 50 16 W |
| Asbury United Methodist Church | Church | 124 | Montgomery | 39 08 33 N | 077 17 52 W |
| Asbury United Methodist Church | Church | 2 | Somerset | 37 58 31 N | 075 50 04 W |
| Asbury United Methodist Church | Church | 16 | Talbot | 38 46 26 N | 076 03 10 W |
| Asbury United Methodist Church | Church | 3 | Talbot | 38 47 39 N | 076 17 39 W |
| Asbury United Methodist Church | Church | 169 | Washington | 39 38 44 N | 077 43 16 W |
| Asbury United Methodist Church | Church | 7 | Wicomico | 38 32 20 N | 075 43 07 W |
| Asbury Woods | Populated Place | 69 | Howard | 39 08 49 N | 076 49 04 W |
| Ascension Cemetery | Cemetery | 134 | Harford | 39 38 48 N | 076 17 33 W |
| Ascension Cemetery | Cemetery | 49 | Prince George's | 39 00 23 N | 076 47 11 W |
| Ascension Church | Church | 57 | Prince George's | 39 00 22 N | 076 47 17 W |
| Ascension Evangelical Lutheran Church | Church | 141 | Baltimore | 39 23 12 N | 076 36 21 W |
| Ascension Lutheran Church | Church | 54 | Prince George's | 38 56 52 N | 076 53 08 W |