| Petersburg | |
| Settlement Type: | Ghost town |
| Pushpin Map: | California |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in California |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Name1: | California |
| Subdivision Type2: | County |
| Subdivision Name2: | Kern County |
| Coordinates: | 35.6025°N -118.6036°W |
| Elevation M: | 1442 |
| Elevation Ft: | 4731 |
Petersburg (also, Petersburgh and Greenhorn) is a former settlement in Kern County, California. It was located on Greenhorn Creek 4.5miles west-northwest of Miracle Hot Springs, at an elevation of 4731 feet (1442 m). Petersburg still appeared on maps as of 1956.
A post office operated at Petersburgh from 1858 to 1863. The place was named for Peter Gardett, early merchant there.