| Ysidro Formation | |
| Type: | Geologic formation |
| Period: | Miocene |
| Age: | Miocene |
| Region: | Baja California |
| Country: | Mexico |
| Overlies: | Bermejo Formation |
| Thickness: | 500feet-1500feetft (-ft) |
The Ysidro Formation is a geologic formation in Baja California state, northwestern Mexico.
It preserves fossils dating back to the Miocene epoch of the Neogene period.