The incident occurred around 10.40am and involved a grey Audi A3, red Skoda Roomster and a grey Range Rover.
Emergency services attended and the 78-year-old male driver and 76-year-old female passenger of the Audi A3 were taken to Aberdeen Royal Infirmary for treatment to serious injuries.
The 83-year-old male driver of the Skoda Roomster was also taken to hospital and has since been released following treatment.
No one else was injured.
The road was closed for around 11 hours whilst a collision investigation was carried out.
Sergeant Eoin Maxwell, of the North East Road Policing Division, said:
Enquiries are ongoing in to the full circumstances surrounding the crash and we are appealing for anyone with any information to get in touch.
I would ask anyone who was in the area at the time to review dashcam footage and contact officers.
Anyone with any information is asked to contact Police Scotland via 101 quoting incident 1064 of Thursday, 30 June, 2022.