Ambulance Victoria said emergency services responded to the crash at Minyip, near Horsham, at about 8.50am today.
Three children and a woman were evacuated from the bus, while emergency workers had to free the trapped driver.
It’s understood the driver suffered serious injuries.
Ambulance Victoria said two people had been taken to hospital via ambulance and a third person had been airlifted to hospital.
Paramedics remain on the scene.
The bus is understood to have belonged to the Warracknabeal Special Developmental School.
