| Unionville, Maryland | |
| Pushpin Map: | USA Maryland |
| Pushpin Label: | Unionville |
| Pushpin Map Caption: | Location in Maryland |
| Coordinates: | 39.4747°N -77.1856°W |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Maryland |
| Subdivision Type2: | County |
| Subdivision Name2: | Frederick |
| Established Title: | First settled |
| Unit Pref: | US |
| Elevation Ft: | 440 |
| Population Density Sq Mi: | auto |
| Blank Name: | GNIS feature ID |
| Blank Info: | 591457 |
Unionville is an unincorporated community in Frederick County, Maryland, United States. It is located approximately halfway between Frederick and Westminster, just east of Libertytown off Maryland Route 26 (Liberty Road). The Pearre-Metcalfe House, which sits on Albaugh Road, just outside the town's center, was listed on the National Register of Historic Places in 1979.
Unionville holds the world record for most rainfall recorded in one minute. On July 4, 1956, 1.23 inches of rain fell in one minute.[1]