Police said traffic had been halted after three vehicles were involved in the collision on the A64 between Malton and York.
The female driver one of the vehicles, a Vauxhall Corsa, was rushed to Leeds General Infirmary.
A North Yorkshire Police spokeswoman said: "Police were contacted at 11.37am to reports of a three-vehicle road traffic collision on the A64 near the Jinnah restaurant at Flaxton, involving a silver Vauxhall Corsa, a black Kia Sorrento and a Mercedes Benz A-class.
"Air ambulance has been requested to attend and the road is currently closed at the Barton-le-Willows turning to allow the emergency services to deal with the collision. Drivers are advised to avoid the area."