The accident took place on a section of the motorway where road works were taking place, between the towns of Neuville-Saint-Vaast and Thélus.
A second vehicle contained four people, a 75-year-old woman and a 45-year-old man, who also died.
The other two passengers in this car were a 14-year-old boy and a 79-year-old man who were in a critical condition.
The third vehicle involved was a car with four passengers, including three children, aged between six and 33.
Prosecutors in nearby Arras have opened an enquiry into the accident.
French regional state prefect Jacques Billant said witnesses to the horrific crash were “being offered psychological counselling”.
The section of the A26 motorway was closed off until late into the night on Sunday, as six emergency medical teams attended the scene.
Around 60 firefighters were also scrambled to the crash site to try to rescue the victims.
The incident occurred at the height of the holiday season, when thousands of British drivers make their way across the Channel.
A UK Foreign Office spokesperson said: “We are in contact with the local authorities following a road traffic accident in France and have offered our assistance to the family.”