Emergency services attended the scene of the collision on the B6271 between Great Langton and Scorton.
It happened near Kiplin Hall around 2.15pm and involved a red Citroen C3 and a black Harley Davidson motorcycle.
The road is closed in both directions and is expected to remain closed for several hours.
Drivers are urged to avoid the area.
Anyone who witnessed the incident is asked to contact police on 101.