One person was critically injured after a truck and the car collided at Wairunga, about 4km south of Palmerston.
A police spokeswoman said emergency responders were called to the SH1 crash at 11.55am.
The injured person was flown to Dunedin Hospital by Otago Regional Rescue Helicopter.
A dog was later also removed safely from the car.
The road was closed but reopened about 2pm. The police serious crash unit had been notified.