| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Ulmstead Acres | city | Maryland | United States | 39.06 | -76.48 | 98 | |
| Ulmstead Cove | city | Maryland | United States | 39.06 | -76.48 | 98 | |
| Ulmstead Estates | city | Maryland | United States | 39.05 | -76.47 | 6 | |
| Ulmstead Gardens | city | Maryland | United States | 39.05 | -76.48 | 49 | |
| Ulmstead Point | city | Maryland | United States | 39.06 | -76.48 | 98 | |
| Underwood (historical) | city | Maryland | United States | 38.51 | -76.75 | 147 | |
| Unicorn | city | Maryland | United States | 39.25 | -75.86 | 49 | |
| Unicorn Crossing | city | Maryland | United States | 39.25 | -75.85 | 42 | |
| Unicorn Manor | city | Maryland | United States | 39.25 | -75.87 | 49 | |
| Union Bridge | city | Maryland | United States | 39.57 | -77.18 | 830 | |
| Union Corner | city | Maryland | United States | 39.03 | -75.81 | 45 | |
| Union Corners | city | Maryland | United States | 38.90 | -75.73 | 52 | |
| Union Hills | city | Maryland | United States | 39.60 | -77.15 | 830 | |
| Union Mills | city | Maryland | United States | 39.67 | -77.02 | 830 | |
| Union Valley | city | Maryland | United States | 39.65 | -75.91 | 213 | |
| Uniontown | city | Maryland | United States | 39.59 | -77.12 | 830 | |
| Unionville | city | Maryland | United States | 38.06 | -75.60 | 16 | |
| Unionville | city | Maryland | United States | 38.81 | -76.14 | 3 | |
| Unionville | city | Maryland | United States | 39.47 | -77.19 | 830 | |
| Unionville Heights | city | Maryland | United States | 38.06 | -75.60 | 13 | |
| Unity | city | Maryland | United States | 39.23 | -77.07 | 830 | |
| University Gardens | city | Maryland | United States | 38.98 | -76.97 | 98 | |
| University Park | city | Maryland | United States | 38.97 | -76.94 | 72 | |
| Upper Brambley (historical) | city | Maryland | United States | 38.30 | -76.81 | 19 | |
| Upper Crest Estates | city | Maryland | United States | 39.53 | -76.32 | 249 | |
| Upper Crossroads | city | Maryland | United States | 39.54 | -76.47 | 830 | |
| Upper Fairmount | city | Maryland | United States | 38.10 | -75.79 | 3 | |
| Upper Falls | city | Maryland | United States | 39.44 | -76.40 | 160 | |
| Upper Ferry Acres | city | Maryland | United States | 38.34 | -75.70 | 19 | |
| Upper Ferry Estates | city | Maryland | United States | 38.34 | -75.69 | 16 | |
| Upper Hill | city | Maryland | United States | 38.11 | -75.79 | 3 | |
| Upper Jutland | city | Maryland | United States | 38.14 | -76.41 | 3 | |
| Upper Marlboro | city | Maryland | United States | 38.82 | -76.75 | 49 | |
| Upper Seneca Crest | city | Maryland | United States | 39.26 | -77.17 | 830 | |
| Upperco | city | Maryland | United States | 39.56 | -76.84 | 830 | |
| Urbana | city | Maryland | United States | 39.33 | -77.35 | 406 | |
| Urbana Overlook | city | Maryland | United States | 39.32 | -77.37 | 830 | |
| Urbanwood | city | Maryland | United States | 39.32 | -76.47 | 16 | |
| Urbs Oceana | city | Maryland | United States | 38.34 | -75.08 | 3 | |
| Urieville | city | Maryland | United States | 39.28 | -76.02 | 45 | |
| Utica | city | Maryland | United States | 39.53 | -77.39 | 301 | |
| Utica Mills Estates | city | Maryland | United States | 39.53 | -77.39 | 351 |