| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Rochelle Meadows | city | Maryland | United States | 39.52 | -76.42 | 830 | |
| Rock | city | Maryland | United States | 39.63 | -76.14 | 49 | |
| Rock Acres | city | Maryland | United States | 39.61 | -76.40 | 416 | |
| Rock Anna | city | Maryland | United States | 39.14 | -76.51 | 59 | |
| Rock Chapel Estates | city | Maryland | United States | 39.50 | -77.36 | 298 | |
| Rock Creek Estates | city | Maryland | United States | 39.16 | -76.51 | 0 | |
| Rock Creek Estates | city | Maryland | United States | 39.43 | -77.43 | 301 | |
| Rock Creek Forest | city | Maryland | United States | 38.99 | -77.06 | 200 | |
| Rock Creek Gardens | city | Maryland | United States | 38.99 | -77.05 | 209 | |
| Rock Creek Hills | city | Maryland | United States | 39.01 | -77.07 | 209 | |
| Rock Creek Knolls | city | Maryland | United States | 39.00 | -77.07 | 196 | |
| Rock Creek Landing | city | Maryland | United States | 39.14 | -76.53 | 85 | |
| Rock Creek Palisades | city | Maryland | United States | 39.04 | -77.08 | 295 | |
| Rock Creek Park | city | Maryland | United States | 39.15 | -76.49 | 55 | |
| Rock Creek Village | city | Maryland | United States | 39.08 | -77.10 | 347 | |
| Rock Hall | city | Maryland | United States | 39.14 | -76.23 | 3 | |
| Rock Hall | city | Maryland | United States | 39.27 | -77.53 | 249 | |
| Rock Hill Beach | city | Maryland | United States | 39.15 | -76.52 | 3 | |
| Rock Manor | city | Maryland | United States | 39.66 | -76.25 | 351 | |
| Rock Point | city | Maryland | United States | 38.27 | -76.84 | 3 | |
| Rock Run | city | Maryland | United States | 39.61 | -76.12 | 75 | |
| Rock Run | city | Maryland | United States | 39.61 | -76.14 | 49 | |
| Rock Run Estates | city | Maryland | United States | 39.63 | -76.13 | 314 | |
| Rock Spring | city | Maryland | United States | 39.57 | -76.38 | 830 | |
| Rock Springs | city | Maryland | United States | 39.72 | -76.16 | 830 | |
| Rockawalking Acres | city | Maryland | United States | 38.38 | -75.68 | 26 | |
| Rockawalking Estates | city | Maryland | United States | 38.36 | -75.68 | 19 | |
| Rockawalking Village | city | Maryland | United States | 38.39 | -75.67 | 32 | |
| Rockaway Beach | city | Maryland | United States | 39.29 | -76.40 | 3 | |
| Rockbrook Trailer Park | city | Maryland | United States | 39.64 | -76.83 | 830 | |
| Rockbrook Village | city | Maryland | United States | 39.64 | -76.83 | 830 | |
| Rockburn Commons | city | Maryland | United States | 39.21 | -76.73 | 180 | |
| Rockcrest | city | Maryland | United States | 39.08 | -77.13 | 400 | |
| Rockdale | city | Maryland | United States | 39.68 | -76.77 | 830 | |
| Rockdale | city | Maryland | United States | 39.36 | -76.77 | 830 | |
| Rockdale | city | Maryland | United States | 39.70 | -77.84 | 830 | |
| Rockdale Manor | city | Maryland | United States | 39.53 | -76.41 | 387 | |
| Rockhill Beach | city | Maryland | United States | 39.14 | -76.52 | 45 | |
| Rockland | city | Maryland | United States | 39.40 | -76.67 | 298 | |
| Rockland | city | Maryland | United States | 39.30 | -76.81 | 830 | |
| Rockland | city | Maryland | United States | 39.07 | -77.13 | 357 | |
| Rockland Estates | city | Maryland | United States | 39.58 | -77.05 | 830 | |
| Rockland Run | city | Maryland | United States | 39.39 | -76.67 | 400 | |
| Rockridge Forest | city | Maryland | United States | 39.65 | -76.38 | 830 | |
| Rockview Beach | city | Maryland | United States | 39.14 | -76.51 | 49 | |
| Rockvilla | city | Maryland | United States | 39.08 | -77.15 | 400 | |
| Rockville | city | Maryland | United States | 39.08 | -77.15 | 400 | |
| Rockwell | city | Maryland | United States | 39.28 | -76.78 | 830 | |
| Rockwood Beach | city | Maryland | United States | 39.16 | -76.48 | 39 | |
| Rocky Acres | city | Maryland | United States | 39.47 | -76.94 | 830 | |
| Rocky Acres | city | Maryland | United States | 39.06 | -76.91 | 147 | |
| Rocky Brook Park | city | Maryland | United States | 39.05 | -77.00 | 396 | |
| Rocky Forge | city | Maryland | United States | 39.72 | -77.60 | 830 | |
| Rocky Gorge Estates | city | Maryland | United States | 39.11 | -76.89 | 265 | |
| Rocky Gorge Meadows | city | Maryland | United States | 39.14 | -76.97 | 337 | |
| Rocky Hook | city | Maryland | United States | 38.48 | -75.93 | 9 | |
| Rocky Ridge | city | Maryland | United States | 39.61 | -77.32 | 393 | |
| Rocky Ridge Estates | city | Maryland | United States | 39.61 | -77.30 | 305 | |
| Rocky Road Park | city | Maryland | United States | 39.24 | -77.17 | 830 | |
| Rocky Springs | city | Maryland | United States | 39.45 | -77.45 | 400 |