The car came off the A92 in Glenrothes, Fife, shortly before 10.30pm on Saturday.
The teenager, who has not been named, was pronounced dead at the scene, between Redhouse and Bankhead.
A second occupant of the car managed to free themselves by the time emergency services arrived.
The northbound carriageway of the A92 at the Thornton bypass was closed afterwards to allow accident investigations.
Police have appealed for witnesses.