| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Orange Grove (historical) | city | Maryland | United States | 39.24 | -76.73 | 190 | |
| Orange Grove (historical) | city | Maryland | United States | 39.24 | -76.75 | 101 | |
| Orangeville | city | Maryland | United States | 39.30 | -76.55 | 49 | |
| Oraville | city | Maryland | United States | 38.42 | -76.69 | 147 | |
| Orchard Beach | city | Maryland | United States | 39.17 | -76.53 | 3 | |
| Orchard Estates | city | Maryland | United States | 39.67 | -77.60 | 830 | |
| Orchard Gate at Piney Orchard | city | Maryland | United States | 39.07 | -76.71 | 196 | |
| Orchard Hill | city | Maryland | United States | 39.22 | -76.10 | 45 | |
| Orchard Hills | city | Maryland | United States | 39.42 | -76.62 | 377 | |
| Orchard Hills | city | Maryland | United States | 39.69 | -77.73 | 830 | |
| Orchard Lakes | city | Maryland | United States | 39.53 | -76.48 | 830 | |
| Orchard Place | city | Maryland | United States | 39.14 | -77.23 | 396 | |
| Orchard Point at Piney Orchard | city | Maryland | United States | 39.07 | -76.71 | 196 | |
| Orchard Pond | city | Maryland | United States | 39.15 | -77.22 | 403 | |
| Orchard View | city | Maryland | United States | 39.68 | -76.08 | 351 | |
| Orchard View | city | Maryland | United States | 39.03 | -76.03 | 49 | |
| Orchard View | city | Maryland | United States | 39.03 | -76.91 | 98 | |
| Orchards of Linthicum | city | Maryland | United States | 39.21 | -76.65 | 147 | |
| Orchardview Estates | city | Maryland | United States | 39.56 | -76.14 | 298 | |
| Oregon | city | Maryland | United States | 39.50 | -76.69 | 351 | |
| Oriole | city | Maryland | United States | 38.17 | -75.81 | 3 | |
| Orme | city | Maryland | United States | 38.64 | -76.77 | 200 | |
| Orr Acres | city | Maryland | United States | 39.13 | -76.51 | 78 |