The girl, from Pickering, died after the blue Vauxhall Corsa she was a passenger in careered off the road and overturned on the A170 Pickering to Scarborough route at Snainton, at around 6.30pm on Saturday. She was pronounced dead at the scene.
The driver of the vehicle, an 18-year-old man from Pickering, was taken to Scarborough District Hospital suffering from slight injuries.
He was discharged yesterday morning and was taken into police custody in connection with the collision.
Another 18-year-old man, also from Pickering, who was driving a white Ford Fiesta, was arrested at the scene of the incident.
Traffic Sgt Neil Campbell said: "It is vital to the investigation that anyone who witnessed the collision gets in touch with the police immediately."
Anyone who witnessed the collision is urged to contact North Yorkshire Police on 0845 60 60 24 7, quoting reference number NYP-08012011-0392.