It happened around 11 p.m. on TC Jester and Cypresswood Drive.
The impact of the crash caused the ambulance to roll at least once with the patient, a medic and driver inside.
All three were transported to hospitals. The 81-year-old woman later died of her injuries, deputies said.
Two people inside the car were also taken to hospitals.
The conditions of the four people were not immediately known, but the car's driver was critical at the time of the crash.
The ambulance, owned by Acadian Ambulance Service, does have a video camera on board and footage was being reviewed by investigators.