| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Harbor Acres | city | Maryland | United States | 38.06 | -75.53 | 22 | |
| Harbor Hills | city | Maryland | United States | 38.46 | -76.59 | 52 | |
| Harbor Hills | city | Maryland | United States | 38.96 | -76.61 | 49 | |
| Harbor Light Beach | city | Maryland | United States | 38.33 | -76.43 | 3 | |
| Harbor Mist Estates | city | Maryland | United States | 38.34 | -75.10 | 3 | |
| Harbor Oaks | city | Maryland | United States | 39.04 | -76.59 | 62 | |
| Harbor Valley Estates | city | Maryland | United States | 39.22 | -76.62 | 98 | |
| Harbor View | city | Maryland | United States | 39.51 | -75.88 | 45 | |
| Harbor View | city | Maryland | United States | 38.89 | -76.50 | 3 | |
| Harborview | city | Maryland | United States | 39.28 | -76.53 | 49 | |
| Harborview | city | Maryland | United States | 38.97 | -76.30 | 3 | |
| Harbour Glen | city | Maryland | United States | 39.03 | -76.51 | 52 | |
| Harbour Oaks | city | Maryland | United States | 39.43 | -76.28 | 3 | |
| Hard Corner | city | Maryland | United States | 38.38 | -76.96 | 98 | |
| Hardesty | city | Maryland | United States | 38.91 | -76.58 | 88 | |
| Hardesty Estates | city | Maryland | United States | 38.93 | -76.62 | 91 | |
| Hardesty Fields | city | Maryland | United States | 38.63 | -76.57 | 101 | |
| Harewood | city | Maryland | United States | 39.37 | -76.34 | 3 | |
| Harewood Park | city | Maryland | United States | 39.38 | -76.37 | 3 | |
| Harford Commons | city | Maryland | United States | 39.42 | -76.30 | 29 | |
| Harford Dale | city | Maryland | United States | 39.55 | -76.36 | 400 | |
| Harford Downs | city | Maryland | United States | 39.60 | -76.49 | 830 | |
| Harford Estates | city | Maryland | United States | 39.56 | -76.38 | 406 | |
| Harford Farms | city | Maryland | United States | 39.41 | -76.52 | 301 | |
| Harford Furnace | city | Maryland | United States | 39.50 | -76.26 | 98 | |
| Harford Heights | city | Maryland | United States | 39.49 | -76.42 | 232 | |
| Harford Heritage | city | Maryland | United States | 39.63 | -76.48 | 830 | |
| Harford Hills | city | Maryland | United States | 39.40 | -76.53 | 370 | |
| Harford Hills | city | Maryland | United States | 39.61 | -76.33 | 308 | |
| Harford Hunt Manor | city | Maryland | United States | 39.55 | -76.49 | 830 | |
| Harford Landing | city | Maryland | United States | 39.43 | -76.26 | 3 | |
| Harford Manor | city | Maryland | United States | 39.43 | -76.27 | 3 | |
| Harford Mobile Village | city | Maryland | United States | 39.44 | -76.32 | 49 | |
| Harford Park | city | Maryland | United States | 39.38 | -76.55 | 344 | |
| Harford Ranchettes | city | Maryland | United States | 39.54 | -76.27 | 308 | |
| Harford Square | city | Maryland | United States | 39.42 | -76.32 | 98 | |
| Harford Village | city | Maryland | United States | 39.56 | -76.37 | 413 | |
| Harford Woods | city | Maryland | United States | 39.54 | -76.34 | 252 | |
| Harkins | city | Maryland | United States | 39.70 | -76.45 | 830 | |
| Harkness Creek Park | city | Maryland | United States | 38.94 | -76.51 | 49 | |
| Harlan Square | city | Maryland | United States | 39.54 | -76.35 | 347 | |
| Harlow | city | Maryland | United States | 39.09 | -77.32 | 298 | |
| Harmans | city | Maryland | United States | 39.16 | -76.70 | 141 | |
| Harmans Woods | city | Maryland | United States | 39.14 | -76.71 | 173 | |
| Harmon Haven | city | Maryland | United States | 39.56 | -77.20 | 830 | |
| Harmon Landing | city | Maryland | United States | 38.20 | -75.26 | 0 | |
| Harmon Landing Estates | city | Maryland | United States | 38.20 | -75.30 | 19 | |
| Harmony | city | Maryland | United States | 38.78 | -75.88 | 49 | |
| Harmony | city | Maryland | United States | 39.49 | -77.53 | 830 | |
| Harmony Corner | city | Maryland | United States | 39.32 | -75.98 | 49 | |
| Harmony Grove | city | Maryland | United States | 39.45 | -77.40 | 298 | |
| Harmony Hall | city | Maryland | United States | 38.75 | -77.00 | 49 | |
| Harmony Hall | city | Maryland | United States | 39.29 | -77.23 | 830 | |
| Harmony Hill | city | Maryland | United States | 39.51 | -77.40 | 298 | |
| Harmony Hills | city | Maryland | United States | 39.07 | -77.08 | 351 | |
| Harmony Hills | city | Maryland | United States | 39.42 | -76.50 | 308 | |
| Harmony Knolls | city | Maryland | United States | 39.50 | -77.54 | 830 | |
| Harness Woods | city | Maryland | United States | 38.94 | -76.50 | 16 | |
| Harney | city | Maryland | United States | 39.71 | -77.21 | 830 | |
| Harney Venture Estates | city | Maryland | United States | 39.71 | -77.29 | 830 | |
| Harold Heights | city | Maryland | United States | 39.51 | -76.30 | 282 | |
| Harp | city | Maryland | United States | 39.53 | -77.53 | 1125 | |
| Harper (historical) | city | Maryland | United States | 38.81 | -76.25 | 3 | |
| Harper Estates | city | Maryland | United States | 39.54 | -76.89 | 830 | |
| Harpers Choice | city | Maryland | United States | 39.22 | -76.88 | 410 | |
| Harpers Mill | city | Maryland | United States | 39.12 | -76.63 | 114 | |
| Harrington | city | Maryland | United States | 39.54 | -76.98 | 849 | |
| Harrington Manor | city | Maryland | United States | 39.42 | -76.53 | 830 | |
| Harris Heights | city | Maryland | United States | 39.55 | -76.92 | 830 | |
| Harris Heights | city | Maryland | United States | 39.20 | -76.62 | 52 | |
| Harris Hill | city | Maryland | United States | 39.72 | -76.64 | 830 | |
| Harrisburg (historical) | city | Maryland | United States | 39.22 | -76.09 | 49 | |
| Harrisonville | city | Maryland | United States | 39.39 | -76.83 | 830 | |
| Harristown | city | Maryland | United States | 39.29 | -76.74 | 830 | |
| Harrisville | city | Maryland | United States | 39.70 | -76.08 | 396 | |
| Harrisville | city | Maryland | United States | 38.48 | -76.19 | 3 | |
| Harrisville | city | Maryland | United States | 39.42 | -77.14 | 830 | |
| Harrisville Farmettes | city | Maryland | United States | 39.44 | -77.19 | 830 | |
| Harrisville Heights | city | Maryland | United States | 39.44 | -77.17 | 830 | |
| Harshman Estates | city | Maryland | United States | 39.50 | -77.55 | 830 | |
| Harshman Estates | city | Maryland | United States | 39.45 | -77.28 | 830 | |
| Harting Estates | city | Maryland | United States | 39.06 | -76.52 | 49 | |
| Hartland Run | city | Maryland | United States | 39.30 | -76.44 | 3 | |
| Hartland Village | city | Maryland | United States | 39.30 | -76.45 | 3 | |
| Hartley (historical) | city | Maryland | United States | 39.45 | -76.47 | 203 | |
| Hartley Hall Estates | city | Maryland | United States | 39.09 | -77.30 | 291 | |
| Hartman | city | Maryland | United States | 39.39 | -77.31 | 830 | |
| Harundale | city | Maryland | United States | 39.15 | -76.61 | 49 | |
| Harvest Acres | city | Maryland | United States | 39.48 | -77.71 | 830 | |
| Harvest Farms | city | Maryland | United States | 39.38 | -76.92 | 830 | |
| Harvest Hills | city | Maryland | United States | 39.54 | -76.44 | 830 | |
| Harvest Hills | city | Maryland | United States | 39.45 | -77.16 | 830 | |
| Harvest Hunt Farm | city | Maryland | United States | 39.09 | -77.28 | 298 | |
| Harvest Ridge | city | Maryland | United States | 39.36 | -77.20 | 830 | |
| Harvey | city | Maryland | United States | 39.70 | -78.28 | 830 | |
| Harwood | city | Maryland | United States | 38.87 | -76.62 | 147 | |
| Harwood Estates | city | Maryland | United States | 38.88 | -76.60 | 98 | |
| Harwood Park | city | Maryland | United States | 39.19 | -76.74 | 98 |