State police have not yet released the names of the people involved.
They say the tractor-trailer was traveling south on Route 19 when it collided with the car that had just entered the road at the intersection of White Creek Road without stopping at the stop sign.
The tractor-trailer left the road and hit a tree, fatally injuring the driver. The driver of the car was taken by Mercy Flight to Strong Memorial Hospital in Rochester.
A state police accident reconstruction team is still on the scene.