The single-vehicle collision happened at 8:20am on the TransCanada Highway at kilometre marker 214, near Meductic.
There were two women and two children in the car. One woman died at the scene and the others were brought to hospital with non-life threatening injuries.
RCMP say it's believed the driver lost control of the vehicle and it rolled several times.
A collision re-constructionist is helping with the investigation.
Traffic was reduced to one lane.
