Emergency services were called to New Road, Woodmancote, at 17:45 BST following reports of the accident
A police spokesman said an off-duty nurse and paramedics tried to save the woman, who was the driver of the car, but she was declared dead at the scene.
The van driver, a 53-year-old man from Cheltenham, was arrested on suspicion of drink driving.
Police are appealing for witnesses.
A woman died in a collision between a car and a van in Gloucestershire.