The Great North Air Ambulance and rapid response paramedics attended the accident on the B6279 Staindrop Road on the outskirts of Darlington.
But despite their efforts, the 58-year-old man from Sadberge, near Darlington, was declared dead at the scene.
The collision, involving a green Kawasaki ZX 750cc bike and a blue Ford Galaxy, happened just before 10.25am yesterday morning (Sunday, July 7) at the junction with Walworth Road.
The 50-year-old driver of the car, from Darlington, was unhurt, as were his wife and two children who were also in the car.
The road was closed until 4pm and police are appealing for any witnesses to the collision.
Anyone who can help is asked to call Durham Police’s collision investigation unit on 0191-375-2159.