The silver Mitsubishi Shogun left the road on a stretch of the A920 Colpy to Oldmeldrum road, near Tocher, at about 16:10 on Sunday afternoon.
Police Scotland said two elderly female passengers were pronounced dead at the scene.
Another woman and the male driver were taken to hospital. Their conditions were described as "critical".
Crash investigations are continuing and officers have appealed for witnesses.
Sgt Chris Whelan said: "This is a very tragic incident involving the deaths of two elderly ladies."