| Blas Ziarreta | |
| Fullname: | Blas Ziarreta Obregón |
| Birth Date: | 6 February 1947 |
| Birth Place: | Santurtzi, Spain |
| Manageryears1: | 1978–1979 |
| Managerclubs1: | Sestao |
| Manageryears2: | 1980–1983 |
| Managerclubs2: | Erandio |
| Manageryears3: | 1984–1985 |
| Managerclubs3: | Santurce |
| Manageryears4: | 1987–1988 |
| Managerclubs4: | Lemona |
| Manageryears5: | 1988–1991 |
| Managerclubs5: | Sestao |
| Manageryears6: | 1991–1993 |
| Managerclubs6: | Bilbao Athletic |
| Manageryears7: | 1993–1996 |
| Managerclubs7: | Sestao |
| Manageryears8: | 1996–1997 |
| Managerclubs8: | Aurrerá Vitoria |
| Manageryears9: | 1997–1998 |
| Managerclubs9: | Burgos |
| Manageryears10: | 1998 |
| Managerclubs10: | Gernika |
| Manageryears11: | 1998–1999 |
| Managerclubs11: | Badajoz |
| Manageryears12: | 1999–2003 |
| Managerclubs12: | Eibar |
Blas Ziarreta Obregón (born 6 February 1947) is a Spanish football manager.