The tragedy happened near the Drumlithie junction at Glenbervie at around 4.30pm on Tuesday.
Police shut the road for almost 24 hours as officers worked to piece together the cause of the accident.
The collision involved three vehicles: A red Renault Megane Scenic, a silver Ford B Max, and a CityLink bus.
Officers have confirmed that a 34-year-old man, who was driving the Renault Megane, has been arrested and charged in relation to road traffic offences following the crash.
He is expected to appear at Aberdeen Sheriff Court in the morning.
We can confirm a 34-year-old man has been charged in connection with a road traffic collision on the #A90 at Glenbervie yesterday where three people died. The man is expected to appear at Aberdeen Sheriff Court on Thursday 14 March.