The Police, Huron County Paramedics and the Hensall Fire Department responded to the scene at approximately 10:11pm on London Road just south of Hensall.
First responders located two heavily damaged sedans that had collided head-on.
The driver of one vehicle, a 27 year old male of Hensall was pronounced at the scene.
Both the driver and passenger of the other care were transported to hospital. The passenger of this vehicle, an 82 year old female of Exeter was later pronounced deceased at hospital. The 86 year old driver also of Exeter remains in hospital with serious injuries.
London Road was closed for several hours for collision investigation but has reopened.
Anyone with information on this collision is asked to contact the OPP at 1-888-310-1122 or 519-482-1677.