Margaret Flynn, 88, from Gloucester, and Barbara Dowdy, 80, from Rockport, Texas, were back-seat passengers in the 4x4 vehicle when it came off the A920 near Tocher in Aberdeenshire on Sunday afternoon.
They were pronounced dead at the scene while the male driver and a woman in the front passenger seat were taken to hospital with serious injuries.
The 74-year-old man and 60-year-old woman remain in a serious but stable condition at Aberdeen Royal Infirmary, police said.
Police, fire and ambulance crews all attended the scene of the single-vehicle crash, which happened at about 4.10pm.
A driver who died after a two-car crash on the A90 Peterhead to Aberdeen road yesterday morning has also been named.
William Duthie, 66, from the Buchan area, died in the collision which happened at around 7am near Stirling Village.
The other driver, who was seriously injured, was airlifted to hospital.
Any witnesses to the collision who have not already spoken to police are being asked to contact officers by calling 101.