Liam Thornton, 26, was injured in the crash on the A956 Charleston Flyover, Aberdeen, at about 6pm on Tuesday.
A four-year-old boy and a woman were also hurt in the collision between a Vauxhall Corsa and a Ford Focus.
Mr Thornton, of Aberdeen, had been a passenger in the Corsa. He was taken to the city's Royal Infirmary for treatment but later died.
Police said the boy and woman were also taken to the hospital. The woman is in a serious condition, while the child is not seriously injured.
Sergeant Rob Warnock, of the Aberdeenshire and Moray Road Policing Unit, said: "Investigations into the cause of the collision are at an early stage and I would ask anyone who saw the collision and has not spoken to police to do so."