| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Jacks Corner | city | Maryland | United States | 39.64 | -76.13 | 305 | |
| Jackson | city | Maryland | United States | 39.58 | -76.04 | 98 | |
| Jackson Grove | city | Maryland | United States | 39.10 | -76.71 | 147 | |
| Jackson Landing | city | Maryland | United States | 38.77 | -76.71 | 49 | |
| Jackson Mill Farms | city | Maryland | United States | 39.63 | -76.03 | 334 | |
| Jackson Ridge | city | Maryland | United States | 39.52 | -76.57 | 830 | |
| Jacksons Corner | city | Maryland | United States | 38.90 | -76.52 | 3 | |
| Jacksontown (historical) | city | Maryland | United States | 38.48 | -77.22 | 88 | |
| Jacksonville | city | Maryland | United States | 39.52 | -76.56 | 830 | |
| Jacktown | city | Maryland | United States | 38.55 | -76.04 | 3 | |
| Jacobs Run | city | Maryland | United States | 39.39 | -77.19 | 830 | |
| Jacobsville | city | Maryland | United States | 39.12 | -76.52 | 95 | |
| James | city | Maryland | United States | 38.59 | -76.26 | 3 | |
| Janwood | city | Maryland | United States | 39.28 | -77.17 | 830 | |
| Jarrettsville | city | Maryland | United States | 39.60 | -76.48 | 830 | |
| Jarrettswood | city | Maryland | United States | 39.59 | -76.46 | 830 | |
| Jasontown | city | Maryland | United States | 39.57 | -77.07 | 830 | |
| Jaycox | city | Maryland | United States | 39.31 | -77.08 | 830 | |
| Jeffers Hill | city | Maryland | United States | 39.20 | -76.83 | 351 | |
| Jefferson | city | Maryland | United States | 39.36 | -77.53 | 830 | |
| Jefferson Court | city | Maryland | United States | 39.36 | -77.54 | 830 | |
| Jefferson Heights | city | Maryland | United States | 39.35 | -77.52 | 830 | |
| Jefferson Heights | city | Maryland | United States | 39.64 | -77.68 | 830 | |
| Jefferson Oaks | city | Maryland | United States | 39.37 | -77.54 | 830 | |
| Jefferson View | city | Maryland | United States | 39.35 | -77.57 | 390 | |
| Jenkins | city | Maryland | United States | 39.48 | -76.48 | 374 | |
| Jenkins Corner | city | Maryland | United States | 38.79 | -76.90 | 249 | |
| Jenkins Landing | city | Maryland | United States | 38.40 | -75.77 | 9 | |
| Jennie Run Estates | city | Maryland | United States | 38.57 | -76.99 | 157 | |
| Jennings | city | Maryland | United States | 39.65 | -79.18 | 2509 | |
| Jennings | city | Maryland | United States | 39.09 | -76.56 | 49 | |
| Jennings Chapel Woods | city | Maryland | United States | 39.27 | -77.07 | 830 | |
| Jensen's Hyde Park | city | Maryland | United States | 38.82 | -76.06 | 49 | |
| Jericho Park | city | Maryland | United States | 39.02 | -76.76 | 147 | |
| Jersey | city | Maryland | United States | 37.97 | -75.86 | 3 | |
| Jersey | city | Maryland | United States | 38.37 | -75.60 | 16 | |
| Jersey Heights | city | Maryland | United States | 38.40 | -75.60 | 22 | |
| Jersey Road Estates | city | Maryland | United States | 38.43 | -75.61 | 39 | |
| Jerusalem | city | Maryland | United States | 39.52 | -77.58 | 830 | |
| Jerusalem | city | Maryland | United States | 39.16 | -77.41 | 370 | |
| Jerusalem | city | Maryland | United States | 39.46 | -76.39 | 147 | |
| Jerusalem Mills | city | Maryland | United States | 39.46 | -76.40 | 193 | |
| Jessie Anne Estates | city | Maryland | United States | 39.58 | -77.12 | 830 | |
| Jessup | city | Maryland | United States | 39.15 | -76.78 | 239 | |
| Jesterville | city | Maryland | United States | 38.29 | -75.90 | 9 | |
| Jewell | city | Maryland | United States | 38.75 | -76.62 | 147 | |
| Jimtown | city | Maryland | United States | 39.60 | -77.39 | 400 | |
| Jocelyn Acres | city | Maryland | United States | 39.20 | -76.98 | 830 | |
| John Town | city | Maryland | United States | 39.43 | -75.92 | 49 | |
| John Walstons Mobile Home Park | city | Maryland | United States | 38.36 | -75.51 | 49 | |
| Johnson Manor | city | Maryland | United States | 39.44 | -76.33 | 49 | |
| Johnsontown | city | Maryland | United States | 39.14 | -76.12 | 3 | |
| Johnstown | city | Maryland | United States | 38.33 | -76.46 | 0 | |
| Johnsville | city | Maryland | United States | 39.53 | -77.23 | 830 | |
| Johnsville | city | Maryland | United States | 39.42 | -76.96 | 830 | |
| Jomar Acres | city | Maryland | United States | 38.72 | -76.98 | 167 | |
| Jonathans Delight | city | Maryland | United States | 39.49 | -76.71 | 830 | |
| Jones | city | Maryland | United States | 39.06 | -76.53 | 49 | |
| Jones | city | Maryland | United States | 39.66 | -77.35 | 830 | |
| Jones Valley | city | Maryland | United States | 39.38 | -76.66 | 360 | |
| Jones View | city | Maryland | United States | 38.56 | -77.13 | 147 | |
| Jonestown | city | Maryland | United States | 38.73 | -75.89 | 45 | |
| Jonestown | city | Maryland | United States | 39.22 | -76.81 | 830 | |
| Jonestown | city | Maryland | United States | 38.26 | -76.44 | 98 | |
| Jonesville | city | Maryland | United States | 39.16 | -77.40 | 400 | |
| Joppa | city | Maryland | United States | 39.43 | -76.36 | 98 | |
| Joppa Acres | city | Maryland | United States | 39.45 | -76.36 | 98 | |
| Joppa Heights | city | Maryland | United States | 39.40 | -76.55 | 400 | |
| Joppa Hills | city | Maryland | United States | 39.51 | -76.37 | 321 | |
| Joppa Landing | city | Maryland | United States | 39.40 | -76.34 | 29 | |
| Joppa Manor | city | Maryland | United States | 39.40 | -76.53 | 370 | |
| Joppa Vale | city | Maryland | United States | 39.39 | -76.47 | 147 | |
| Joppa View | city | Maryland | United States | 39.40 | -76.47 | 173 | |
| Joppatowne | city | Maryland | United States | 39.46 | -76.36 | 164 | |
| Jordan Mill Farms | city | Maryland | United States | 39.69 | -76.61 | 830 | |
| Josenhans | city | Maryland | United States | 39.32 | -76.45 | 3 | |
| Joseph Meadows | city | Maryland | United States | 39.62 | -77.11 | 830 | |
| Joy Haven | city | Maryland | United States | 39.51 | -75.95 | 62 | |
| Joy Lee Acres | city | Maryland | United States | 38.61 | -76.59 | 52 | |
| Joyce | city | Maryland | United States | 39.02 | -76.52 | 3 | |
| Joyce Acres | city | Maryland | United States | 39.04 | -76.50 | 98 | |
| Jugtown | city | Maryland | United States | 39.61 | -77.59 | 1076 | |
| Julian Woods | city | Maryland | United States | 39.38 | -76.76 | 830 | |
| Jumptown | city | Maryland | United States | 38.96 | -75.92 | 49 | |
| June Acres | city | Maryland | United States | 39.61 | -77.51 | 1840 | |
| Justice Heights | city | Maryland | United States | 38.38 | -75.55 | 32 | |
| Justifiable | city | Maryland | United States | 39.33 | -77.03 | 830 |