Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Jarrettsville Park | Park | 169 | Harford | 39 35 20 N | 076 30 21 W |
| Jarrettsville Plaza Shopping Center | Locale | 201 | Harford | 39 36 20 N | 076 28 38 W |
| Jarrettsville Post Office | Post Office | 198 | Harford | 39 36 25 N | 076 28 39 W |
| Jarrettsville Recreation Complex | Park | 217 | Harford | 39 36 10 N | 076 29 27 W |
| Jarrettsville United Methodist Church | Church | 205 | Harford | 39 36 18 N | 076 28 29 W |
| Jarrettsville Volunteer Fire Company | Building | | Harford | 40 01 46 N | 076 48 04 W |
| Jarrettswood | Populated Place | 178 | Harford | 39 35 24 N | 076 27 48 W |
| Jason Creek | Stream | | Somerset | 38 13 40 N | 075 46 54 W |
| Jasontown | Populated Place | 161 | Carroll | 39 34 05 N | 077 04 12 W |
| Java Farms | Locale | 14 | Anne Arundel | 38 53 17 N | 076 33 16 W |
| Jaycox | Populated Place | 174 | Howard | 39 18 26 N | 077 04 59 W |
| Jean Brook | Stream | | Anne Arundel | 38 52 38 N | 076 34 42 W |
| Jean Roberts Memorial Park | Park | 1 | Harford | 39 33 13 N | 076 05 27 W |
| Jeans Gut | Gut | 1 | Somerset | 37 58 20 N | 076 01 53 W |
| Jeffers Chapel United Methodist Church | Church | 13 | Queen Anne's | 39 11 03 N | 075 53 29 W |
| Jeffers Hill | Populated Place | 115 | Howard | 39 12 05 N | 076 49 39 W |
| Jeffers Hill Elementary School | School | 123 | Howard | 39 12 19 N | 076 49 36 W |
| Jefferson | Populated Place | 178 | Frederick | 39 21 43 N | 077 31 54 W |
| Jefferson Cemetery | Cemetery | 179 | Frederick | 39 21 45 N | 077 31 58 W |
| Jefferson Court | Populated Place | 181 | Frederick | 39 21 35 N | 077 32 24 W |
| Jefferson Fire Company Number 20 | Building | | Frederick | 39 36 10 N | 077 53 17 W |
| Jefferson Heights | Populated Place | 212 | Frederick | 39 21 08 N | 077 31 20 W |
| Jefferson Heights | Populated Place | 170 | Washington | 39 38 38 N | 077 40 37 W |
| Jefferson Island | Island | 0 | Talbot | 38 46 04 N | 076 22 19 W |
| Jefferson Memorial Church | Church | 0 | Dorchester | 38 28 23 N | 076 16 29 W |
| Jefferson Oaks | Populated Place | 138 | Frederick | 39 22 18 N | 077 32 39 W |
| Jefferson Patterson Historical Park | Park | 14 | Calvert | 38 24 00 N | 076 30 29 W |
| Jefferson Patterson Museum | Building | 14 | Calvert | 38 24 00 N | 076 30 29 W |
| Jefferson Post Office | Post Office | 168 | Frederick | 39 21 40 N | 077 32 32 W |
| Jefferson School | School | 111 | Harford | 39 32 00 N | 076 12 53 W |
| Jefferson School (historical) | School | 116 | Cecil | 39 39 18 N | 076 02 49 W |
| Jefferson Union Cemetery | Cemetery | 178 | Frederick | 39 21 46 N | 077 32 07 W |
| Jefferson United Church of Christ | Church | 181 | Frederick | 39 21 40 N | 077 32 08 W |
| Jefferson United Methodist Church | Church | 178 | Frederick | 39 21 44 N | 077 31 58 W |
| Jefferson View | Populated Place | 134 | Frederick | 39 20 42 N | 077 34 05 W |
| Jeffrey House | Building | | Baltimore | 39 24 24 N | 076 35 30 W |
| Jehovah Witness Kingdom Hall | Church | 67 | Howard | 39 07 04 N | 076 51 11 W |
| Jenkins | Populated Place | 108 | Baltimore | 39 28 55 N | 076 28 51 W |
| Jenkins Corner | Populated Place | 76 | Prince George's | 38 47 11 N | 076 53 50 W |
| Jenkins Creek | Bay | -3 | Somerset | 37 57 35 N | 075 51 16 W |
| Jenkins Creek | Stream | | Dorchester | 38 34 58 N | 076 06 48 W |
| Jenkins Creek | Stream | | Worcester | 38 20 41 N | 075 07 38 W |
| Jenkins Hill | Summit | 816 | Garrett | 39 35 37 N | 079 08 15 W |
| Jenkins Landing | Populated Place | 4 | Wicomico | 38 24 04 N | 075 46 18 W |
| Jenkins Memorial Church | Church | 10 | Anne Arundel | 39 09 34 N | 076 30 53 W |
| Jenkins Memorial Hospital | Hospital | 51 | Baltimore (city) | 39 16 10 N | 076 40 21 W |
| Jenkins Neck | Cape | 1 | Worcester | 38 23 07 N | 075 08 30 W |
| Jenkins Point | Cape | 0 | Worcester | 38 23 06 N | 075 07 26 W |
| Jenkins Run | Stream | | Baltimore | 39 27 46 N | 076 33 35 W |
| Jenkins Run | Stream | | Charles | 38 23 46 N | 076 52 14 W |
| Jennie Run | Stream | | Charles | 38 32 46 N | 077 01 01 W |
| Jennie Run Estates | Populated Place | 51 | Charles | 38 33 57 N | 076 59 16 W |
| Jennifer Branch | Stream | | Baltimore | 39 25 15 N | 076 29 59 W |
| Jenning Road Recreation Area | Park | 14 | Anne Arundel | 39 04 53 N | 076 33 31 W |
| Jennings | Populated Place | 26 | Anne Arundel | 39 05 25 N | 076 33 48 W |
| Jennings | Populated Place | 670 | Garrett | 39 38 47 N | 079 10 57 W |
| Jennings Chapel United Methodist Church | Church | 194 | Howard | 39 18 01 N | 077 06 04 W |
| Jennings Chapel Woods | Populated Place | 162 | Howard | 39 16 07 N | 077 04 19 W |
| Jennings Run | Stream | | Allegany | 39 41 41 N | 078 47 10 W |
| Jennings Run | Stream | | Garrett | 39 24 59 N | 079 10 55 W |
| Jenny Island | Island | 0 | Dorchester | 38 13 36 N | 076 03 18 W |
| Jericho Covered Bridge | Bridge | 36 | Harford | 39 27 35 N | 076 23 15 W |
| Jericho Marsh | Swamp | 0 | Somerset | 38 04 20 N | 075 51 57 W |
| Jericho Park | Populated Place | 42 | Prince George's | 39 01 04 N | 076 45 54 W |
| Jerrys Cove | Bay | 0 | Kent | 39 06 34 N | 076 12 21 W |
| Jerrys Drain | Stream | | Wicomico | 38 22 20 N | 075 49 58 W |
| Jersey | Populated Place | 1 | Somerset | 37 58 27 N | 075 51 39 W |
| Jersey | Populated Place | 5 | Wicomico | 38 22 28 N | 075 36 17 W |
| Jersey Heights | Populated Place | 12 | Wicomico | 38 23 46 N | 075 35 59 W |
| Jersey Island | Island | 0 | Somerset | 37 57 50 N | 075 51 35 W |
| Jersey Road Estates | Populated Place | 13 | Wicomico | 38 25 50 N | 075 36 25 W |
| Jerusalem | Populated Place | 47 | Baltimore | 39 27 46 N | 076 23 21 W |
| Jerusalem | Populated Place | 244 | Frederick | 39 31 27 N | 077 34 48 W |
| Jerusalem | Populated Place | 127 | Montgomery | 39 09 33 N | 077 24 22 W |
| Jerusalem Cemetery | Cemetery | 206 | Carroll | 39 39 45 N | 076 56 52 W |
| Jerusalem Cemetery | Cemetery | 247 | Frederick | 39 31 23 N | 077 34 46 W |
| Jerusalem Cemetery | Cemetery | 27 | Wicomico | 38 23 11 N | 075 28 18 W |
| Jerusalem Church | Church | 204 | Carroll | 39 39 44 N | 076 56 53 W |
| Jerusalem Church | Church | 112 | Harford | 39 28 02 N | 076 22 19 W |
| Jerusalem Evangelical Lutheran Church | Church | 57 | Baltimore (city) | 39 19 51 N | 076 33 40 W |
| Jerusalem Evangelical Lutheran Church | Church | 120 | Harford | 39 42 09 N | 076 22 20 W |
| Jerusalem Holiness Church | Church | 71 | Baltimore (city) | 39 18 16 N | 076 40 16 W |
| Jerusalem Lutheran Church (historical) | Church | 247 | Frederick | 39 31 25 N | 077 34 46 W |
| Jerusalem Mills | Populated Place | 70 | Baltimore | 39 27 30 N | 076 24 06 W |
| Jerusalem United Methodist Church | Church | 26 | Wicomico | 38 23 12 N | 075 28 18 W |
| Jessica Brook | Stream | | Anne Arundel | 38 53 29 N | 076 34 39 W |
| Jessie Anne Estates | Populated Place | 164 | Carroll | 39 34 40 N | 077 07 09 W |
| Jessie B Mason Regional School | School | 85 | Prince George's | 38 50 15 N | 076 57 03 W |
| Jessops Church | Church | 169 | Baltimore | 39 30 25 N | 076 38 26 W |
| Jessup | Populated Place | 66 | Anne Arundel | 39 08 57 N | 076 46 31 W |
| Jessup Blair Park | Park | 101 | Montgomery | 38 59 06 N | 077 01 26 W |
| Jessup Elementary School | School | 84 | Anne Arundel | 39 08 43 N | 076 46 04 W |
| Jessup Fire Company 29 | Building | | Anne Arundel | 39 08 16 N | 076 45 14 W |
| Jessup Park | Park | 74 | Anne Arundel | 39 09 07 N | 076 45 20 W |
| Jessup Post Office | Post Office | 86 | Anne Arundel | 39 08 31 N | 076 45 43 W |
| Jessup Volunteer Fire Department | Building | | Anne Arundel | 39 14 18 N | 077 15 33 W |
| Jessup-Dorsey Park | Park | 54 | Anne Arundel | 39 09 51 N | 076 44 36 W |
| Jessup-Provinces Park | Park | 74 | Anne Arundel | 39 07 50 N | 076 43 46 W |
| Jesterville | Populated Place | 3 | Wicomico | 38 17 12 N | 075 53 45 W |
| Jewell | Populated Place | 47 | Anne Arundel | 38 45 17 N | 076 37 07 W |
| Jewish Community Center | Building | 135 | Baltimore (city) | 39 21 10 N | 076 41 12 W |
| Jewish Community Center | Building | 111 | Montgomery | 39 03 12 N | 077 07 30 W |
| Jewish Heritage Center | Building | 6 | Baltimore (city) | 39 17 24 N | 076 36 04 W |
| Jewish Museum of Maryland | Building | | Baltimore (city) | 39 17 25 N | 076 36 04 W |
| Jigger Hill | Summit | 341 | Frederick | 39 25 41 N | 077 29 50 W |
| Jimmy Island | Island | 0 | St. Mary's | 38 06 26 N | 076 28 03 W |
| Jims Gut | Gut | 0 | Worcester | 38 06 17 N | 075 12 17 W |
| Jimson Weed Marsh | Swamp | 0 | Dorchester | 38 15 22 N | 076 05 11 W |
| Jimson Weed Point | Cape | 10 | Dorchester | 38 15 13 N | 076 05 57 W |
| Jimtown | Populated Place | 128 | Frederick | 39 35 57 N | 077 23 34 W |