Henry Surtees, the teenage son of 1964 Formula One champion John, died on Sunday after an accident in a Formula Two race at Brands Hatch.
A spokeswoman for the Royal London hospital confirmed the 18-year-old had died after being flown there from Brands Hatch circuit in southern England.
Surtees was hit on the head by a loose wheel and tyre from the car of a rival who had crashed.
Organisers said the blow knocked him unconscious, with his car then smashing into the barriers. The race was stopped immediately.
Formula Two chief executive Jonathan Palmer said in a statement that the accident raised "high levels of concern" and his thoughts were with the Surtees family.
John Surtees won his title with Ferrari and remains the only man to have won world titles on two wheels and four.
His son had taken his first podium finish in the new series only on Saturday, with third place.
