The 20-year-old was a passenger in a car which overturned on Derek Dooley Way, in Sheffield, in the early hours of this morning.
The car was heading away from the Parkway, around 4am, when the accident happened, close to the junction with The Wicker.
The 20-year-old’s injuries were described as “life threatening.”
The 22-year-old driver was also taken to hospital with serious injuries.
A second passenger, an 18-year-old man, suffered minor injuries.
Police are appealing for anyone who was in the area at the time and saw what happened to contact them on 101.