Theresa Franz, 49, Norwalk, was driving a 2003 Pontiac Grand AM that drove off the roadway at about 9:40 p.m. Monday.
Franz was eastbound on Washington Road west of Halfway Road in Ridgefield Township, according to the Ohio Highway Patrol.
Alcohol is being investigated as a contributing factor in the one-vehicle accident, the Patrol said.
The car overturned several times and came to a rest on its roof in a field. Franz, who was thrown from the vehicle and sustained critical injuries, was transported from the scene to Cleveland Metro Hospital.
No charges have been filed and alcohol is considered a factor in the crash. The crash remains under investigation.