A pensioner was found dead behind the wheel of his car after it left a road, mounted a kerb and collided with a concrete post and tree.
Emergency services were alerted to the collision on Birley Moor Road, Hackenthorpe, at 10.40am on Tuesday.
The driver of the blue Chevrolet Aveo was pronounced dead at the scene.
Police said the car was travelling towards Owlthorpe at the time of the collision.
The motorist has not yet been formally identify but his relatives have been informed of the tragedy.
A South Yorkshire Police spokeswoman said: “No other vehicles were involved. Officers would like to speak to anyone who witnessed the collision or saw the car in the moments leading up to the incident.”