| Site of Special Scientific Interest | |
| Location | Wales |
|---|---|
| Grid reference | SS9285196797 |
| Coordinates | 51°39′35″N3°33′02″W / 51.659709°N 3.5504665°W |
| Interest | Biological |
| Area | 323.88 ha |
| Notification | 1 January 1972 |
Mynydd Ty-Isaf, Rhondda is a Site of Special Scientific Interest near Treherbert in Rhondda Cynon Taf, south Wales.