| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Jacks Corner | city | Maryland | United States | 39.64139 | -76.12667 | 305 | 9225 |
| Jackson | city | Maryland | United States | 39.5825 | -76.04222 | 98 | 17088 |
| Jackson Grove | city | Maryland | United States | 39.10389 | -76.70861 | 147 | 45683 |
| Jackson Landing | city | Maryland | United States | 38.77278 | -76.71028 | 49 | 13565 |
| Jackson Mill Farms | city | Maryland | United States | 39.63389 | -76.03333 | 334 | 10482 |
| Jackson Ridge | city | Maryland | United States | 39.52222 | -76.57111 | 597 | 15655 |
| Jacksons Corner | city | Maryland | United States | 38.90278 | -76.51806 | 3 | 24904 |
| Jacksontown historical | city | Maryland | United States | 38.47833 | -77.22333 | 88 | 2624 |
| Jacksonville | city | Maryland | United States | 39.51806 | -76.55972 | 570 | 15655 |
| Jacktown | city | Maryland | United States | 38.55194 | -76.04306 | 3 | 13073 |
| Jacobs Run | city | Maryland | United States | 39.38833 | -77.18861 | 688 | 11809 |
| Jacobsville | city | Maryland | United States | 39.12139 | -76.51778 | 95 | 76259 |
| James | city | Maryland | United States | 38.58556 | -76.25889 | 3 | 1095 |
| Janwood | city | Maryland | United States | 39.27639 | -77.16972 | 600 | 18491 |
| Jarrettsville | city | Maryland | United States | 39.60444 | -76.47806 | 606 | 12451 |
| Jarrettswood | city | Maryland | United States | 39.59 | -76.46361 | 547 | 12451 |
| Jasontown | city | Maryland | United States | 39.56806 | -77.07028 | 538 | 16852 |
| Jaycox | city | Maryland | United States | 39.30722 | -77.08333 | 498 | 8102 |
| Jeffers Hill | city | Maryland | United States | 39.20139 | -76.82778 | 351 | 91354 |
| Jefferson | city | Maryland | United States | 39.36194 | -77.53194 | 551 | 10210 |
| Jefferson Court | city | Maryland | United States | 39.35972 | -77.54028 | 505 | 10210 |
| Jefferson Heights | city | Maryland | United States | 39.64389 | -77.67722 | 557 | 49387 |
| Jefferson Heights | city | Maryland | United States | 39.35222 | -77.5225 | 813 | 10210 |
| Jefferson Oaks | city | Maryland | United States | 39.37167 | -77.54444 | 524 | 8890 |
| Jefferson View | city | Maryland | United States | 39.345 | -77.56833 | 390 | 8890 |
| Jenkins | city | Maryland | United States | 39.48194 | -76.48111 | 374 | 17467 |
| Jenkins Corner | city | Maryland | United States | 38.78639 | -76.8975 | 249 | 66570 |
| Jenkins Landing | city | Maryland | United States | 38.40111 | -75.77194 | 9 | 2476 |
| Jennie Run Estates | city | Maryland | United States | 38.56583 | -76.98806 | 157 | 20439 |
| Jennings | city | Maryland | United States | 39.64639 | -79.18278 | 2198 | 2007 |
| Jennings | city | Maryland | United States | 39.09028 | -76.56361 | 49 | 86969 |
| Jennings Chapel Woods | city | Maryland | United States | 39.26861 | -77.07222 | 472 | 7412 |
| Jericho Park | city | Maryland | United States | 39.01778 | -76.76528 | 147 | 33562 |
| Jersey | city | Maryland | United States | 37.97417 | -75.86111 | 3 | 4188 |
| Jersey | city | Maryland | United States | 38.37444 | -75.605 | 16 | 43012 |
| Jersey Heights | city | Maryland | United States | 38.39611 | -75.6 | 22 | 37480 |
| Jersey Road Estates | city | Maryland | United States | 38.43056 | -75.60722 | 39 | 16218 |
| Jerusalem | city | Maryland | United States | 39.52417 | -77.58028 | 826 | 6050 |
| Jerusalem | city | Maryland | United States | 39.15917 | -77.40639 | 370 | 3961 |
| Jerusalem | city | Maryland | United States | 39.46278 | -76.38944 | 147 | 29721 |
| Jerusalem Mills | city | Maryland | United States | 39.45833 | -76.40194 | 193 | 29938 |
| Jessie Anne Estates | city | Maryland | United States | 39.57778 | -77.11944 | 498 | 8593 |
| Jessup | city | Maryland | United States | 39.14917 | -76.77556 | 239 | 53194 |
| Jesterville | city | Maryland | United States | 38.28667 | -75.89611 | 6 | 984 |
| Jewell | city | Maryland | United States | 38.75472 | -76.61889 | 147 | 12029 |
| Jimtown | city | Maryland | United States | 39.59917 | -77.39306 | 400 | 8837 |
| Jocelyn Acres | city | Maryland | United States | 39.19556 | -76.97778 | 498 | 16117 |
| John Town | city | Maryland | United States | 39.42556 | -75.91889 | 49 | 2885 |
| Johnson Manor | city | Maryland | United States | 39.43917 | -76.32889 | 49 | 51682 |
| Johnsontown | city | Maryland | United States | 39.1375 | -76.11694 | 3 | 2490 |
| Johnstown | city | Maryland | United States | 38.32889 | -76.46389 | 0 | 17209 |
| Johnsville | city | Maryland | United States | 39.53389 | -77.23111 | 600 | 5198 |
| Johnsville | city | Maryland | United States | 39.41639 | -76.9575 | 649 | 22563 |
| Jomar Acres | city | Maryland | United States | 38.72361 | -76.98 | 167 | 43714 |
| Jonathans Delight | city | Maryland | United States | 39.48556 | -76.70694 | 600 | 24161 |
| Jones | city | Maryland | United States | 39.65972 | -77.35361 | 449 | 8511 |
| Jones | city | Maryland | United States | 39.05611 | -76.52944 | 98 | 57228 |
| Jones Valley | city | Maryland | United States | 39.38306 | -76.665 | 360 | 170443 |
| Jones View | city | Maryland | United States | 38.56278 | -77.12639 | 147 | 9925 |
| Jonestown | city | Maryland | United States | 39.22194 | -76.80778 | 449 | 92853 |
| Jonestown | city | Maryland | United States | 38.25611 | -76.43917 | 98 | 16889 |
| Jonestown | city | Maryland | United States | 38.72944 | -75.89167 | 45 | 3570 |
| Jonesville | city | Maryland | United States | 39.1575 | -77.3975 | 400 | 3961 |
| Joppa | city | Maryland | United States | 39.43361 | -76.35806 | 98 | 46968 |
| Joppa Acres | city | Maryland | United States | 39.45 | -76.36361 | 98 | 46968 |
| Joppa Heights | city | Maryland | United States | 39.40194 | -76.54639 | 400 | 202144 |
| Joppa Hills | city | Maryland | United States | 39.50917 | -76.37139 | 321 | 50737 |
| Joppa Landing | city | Maryland | United States | 39.40278 | -76.33944 | 29 | 41313 |
| Joppa Manor | city | Maryland | United States | 39.39667 | -76.53194 | 370 | 154384 |
| Joppa Vale | city | Maryland | United States | 39.39389 | -76.46889 | 147 | 101940 |
| Joppa View | city | Maryland | United States | 39.40278 | -76.47111 | 170 | 101940 |
| Joppatowne | city | Maryland | United States | 39.45778 | -76.35556 | 164 | 46968 |
| Jordan Mill Farms | city | Maryland | United States | 39.68694 | -76.60889 | 698 | 7633 |
| Josenhans | city | Maryland | United States | 39.31611 | -76.44917 | 3 | 91881 |
| Joseph Meadows | city | Maryland | United States | 39.62 | -77.11 | 505 | 8108 |
| Joy Haven | city | Maryland | United States | 39.51083 | -75.95278 | 62 | 6985 |
| Joy Lee Acres | city | Maryland | United States | 38.6125 | -76.59306 | 52 | 11991 |
| Joyce | city | Maryland | United States | 39.02472 | -76.52028 | 3 | 68838 |
| Joyce Acres | city | Maryland | United States | 39.03833 | -76.50417 | 98 | 68838 |
| Jugtown | city | Maryland | United States | 39.6125 | -77.59417 | 1076 | 9189 |
| Julian Woods | city | Maryland | United States | 39.37556 | -76.75833 | 449 | 87842 |
| Jumptown | city | Maryland | United States | 38.96111 | -75.91889 | 49 | 2248 |
| June Acres | city | Maryland | United States | 39.61056 | -77.51167 | 1840 | 5073 |
| Justice Heights | city | Maryland | United States | 38.37528 | -75.55111 | 32 | 30714 |
| Justifiable | city | Maryland | United States | 39.32722 | -77.02972 | 649 | 9653 |
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