| Tassajara | |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | California |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in California |
| Coordinates: | 37.7958°N -121.8636°W |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | California |
| Subdivision Type2: | County |
| Subdivision Name2: | Contra Costa County |
| Elevation Ft: | 709 |
| Elevation M: | 216 |
| Blank Name: | GNIS ID[1] [2] |
| Blank1 Name: | FIPS code |
| Blank1 Info: | 06-77973 |
Tassajara, a variation of the Spanish word "tasajera" (Spanish for "place where the meat is hung" or "meat drier"),[3] is an unincorporated community in Contra Costa County, California, United States.[1] It is located on the east bank of Tassajara Creek, 6.5miles south-southeast of Mount Diablo, at an elevation of 709 feet (216 m).[1] Together with Blackhawk it forms the Blackhawk-Camino Tassajara census designated place (CDP).
Until 1959, it was known as Tassajero;.[1]
A post office operated at Tassajara from 1896 to 1922.