The woman was traveling in a car with a 20-year-old man, who for unclear reasons lost control of the car.
-We do not know what happened, but the car went through a game fence and out into a field and as far as we understand, the woman died immediately, says Daniel Ågren, officer at the police's regional command center.
The man was injured in the accident and taken to hospital.
-It is unclear how seriously injured he is, says Daniel Ågren.
The car has been seized for technical inspection.
The road in the direction of Stockholm was closed for several hours due to the rescue work, but is now open for traffic again.
The couple in the accident car were residents of Uppsala.